Answer:
66 1/6ft
Step-by-step explanation:
I have calculated by saying perimeter =2(length+width). I think that's the answer hope it helps.
Answer: 46 1/4
Step-by-step explanation:
Perimeter = (L+W) x 2
So basically ... (10 1/4 + 12 5/6) x 2
Which would be ... 23 1/12 x 2
Which gives you the answer of 46 and 1/4
(Factoring Algebraic Expressions MC)
x3y2 is the result of the expression employing the common factor (x - 6y).
What is Mathematical expression?Here,
The sentence is,
x⁴y² - 6x³y³
We must use the common factor to solve.
Mathematical expression refers to the combining of numbers and variables utilizing the operations addition, subtraction, multiplication, and division.
Now,
The sentence is,
x⁴y² - 6x³y³
The common factor is used to solve as,
6x3y3 - x4y2 equals x*x*x*y*y - 6*x*x*x*y*y.
= x³y² (x - 6y) (x - 6y)
Consequently, x3y2 is the value of the expression employing the common factor (x - 6y).
To Learn more About common factor refer To:
https://brainly.com/question/219464
#SPJ1
Sukie interviewed 125 employees at her company and discovered that 21 of them planned to take an extended vacation next year.
What is the 95% confidence interval for this population proportion? Answer choices are rounded to the hundredths place.
The 95% confidence interval for this population proportion is (0.10, 0.23).
What is a confidence interval?A confidence interval is a range of values that are constrained by the statistic's mean and that are likely to include an unidentified population parameter. The proportion of likelihood, or certainty, that the confidence interval would include the real population parameter when a random sample is drawn several times is referred to as the confidence level.
Sample size n = 125
number of people who planned to take an extended vacation = 21
sample proportion p = 21/125 = 0.168
Confidence level = 0.95
significance level α = 1-0.95 = 0.05
Z score =[tex]Z_{\alpha 2}[/tex] = Z(0.05) = 1.96, from Z table.
The confidence interval for population proportion is-
p±[tex]Z_{\alpha 2}[/tex] x √{p(1-p)}/n =0.168±1.96 x 0.168 x √{(1-0.168)}/125
=0.168±1.96 x 0.0334
=0.168±0.0655
=(0.1025, 0.2335)
=(0.10, 0.23)
Therefore, the confidence interval is (0.10, 0.23).
To learn more about the confidence interval;
https://brainly.com/question/24131141
#SPJ1
Some values of f(x, y) are given below. Write out the terms of a Riemann Sum (using four squares) that gives an upper estimate of r 4 0 r 4 0 f dx dy.
To find a Riemann sum that gives an upper estimate of the double integral, we need to divide the region of integration into small subregions (in this case, squares) and take the maximum value of f(x, y) over each subregion.
The Riemann sum will then be the sum of the areas of the subregions times the maximum value of f(x, y) over each subregion.
For example, if we divide the region of integration into four squares, the Riemann sum would be given by:
Riemann sum = (area of first square) * (maximum value of f(x, y) in first
square) + (area of second square) * (maximum value of
f(x, y) in second square) + (area of third square) *
(maximum value of f(x, y) in third square) + (area of fourth
square) * (maximum value of f(x, y) in fourth square)
We can then fill in the specific values of the areas and maximum values of f(x, y) for each square based on the given values of f(x, y).
Learn more about Reimann Sum here:
https://brainly.com/question/14418174
#SPJ4
Steven found that between 2012 and 2020, as a country's per capita chicken egg consumption increased, the country's divorce rate decreased. Based on this information, which of the following conclusions is valid?
O Eating chicken eggs prevents divorces.
O Divorces lead to a decrease in per capita chicken egg consumption.
O There is a positive association between per capita chicken egg consumption and divorce rate.
O There is a negative association between per capita chicken egg consumption '.' and divorce rate
There is a positive association between per capita chicken egg consumption and divorce rate is true.
Define statement.A statement in mathematics is a declarative utterance that can only be either true or false. A proposal is another name for a statement. It's important that there be no ambiguity. A sentence can only be true or untrue and not both for it to be a statement.
Give example of statement.A meaningful string of words that can be either true or incorrect makes up a mathematical statement. They are referred to simply as a statement. For instance, "ABC is an equilateral triangle" could be denoted by the letter "p." As a result, in an equilateral triangle, p = ABC.
There is a positive association between per capita chicken egg consumption and divorce rate is the correct and valid statement according to the given presented situation.
To learn more about statement visit the link:
https://brainly.com/question/25046487
#SPJ4
Anne Richards purchased two slippers at one price and three pajamas at another price. Let s = the price of each slipper and p = the price of each pajama. Each slipper
cost $12. How much did each pajama cost if the total purchase price was $120?
Each pajama cost $. (Simplify your answer.)
Answer:
[tex]E[/tex]ach pajama costs $32
Step-by-step explanation:
So, the said person bought:
2 slippers at a price, 3 pajamas at another price. (The prices are unknowns, s, and p)
Each slippers cost $12
We are to find the cost of each pajama, where the total purchase price is $120
With the given conditions, we formulate an equation: 2s + 3p = 120
Since s = 12, we replace for the value of s in the equation. s becomes 2 × 12 = 24.
The new equation is then: 24 + 3p = 120, where we are to find the value of p.
Collect like terms: 3p = 120 - 24 → 3p = 96
Divide both sides of the equation by 3 to find the value of p: 3p/3 = 96/3 → p = 32
Therefore, the price of each pajama is $32
I hope this helpsA researcher at the Centers for Disease Control and Prevention is studying the growth of a certain bacteria. He starts his experiment with 500 bacteria that grow at a rate of 18% per hour. He will check on the bacteria every 3 hours. How many bacteria will he find in 3 hours? Round your answer to the nearest whole number.
Answer:
The answer is approximately 770 bacteria after 3 hours.
pls help me with both of these questions
The number of times a large popcorn without butter is sold is, 49.
The conditional relative frequency of no.of Item2 sold given that
50% off is 0.27.
What is conditional probability?Conditional probability is a term used in probability theory to describe the likelihood that one event will follow another given the occurrence of another event.
The number of times a large popcorn without butter is sold is,
= 49.
The total no. of items that is 50% off is (12 + 20 + 32) = 74.
The no. of Item2 which is 50% off is 20.
So, The conditional relative frequency of no.of Item2 sold given that 50% off is,
= 20/74.
= 0.27.
learn more about conditional relative frequency here :
https://brainly.com/question/8358304
#SPJ1
Solve the following inequality.4x+6<3x+3
Answer:
x < - 3
Step-by-step explanation:
4x + 6 < 3x + 3 ( subtract 3x from both sides )
x + 6 < 3 ( subtract 6 from both sides )
x < - 3
Answer:
x < -3
Step-by-step explanation:
4x+6<3x+3
= 4x+6-3x<3
= 4x-3x<3-6
4x-3x<3-6
=x<3-6
x<-3
calculating Nominal GDP, Real GDP, and other economic indicators and can successfully use these indicators to draw conclusions because…
You can successfully use nominal GDP, real GDP, and other economic indicators to draw conclusions because they health of the country's economy.
What is GDP?GDP stands for Gross Domestic Product. This is a very common economic indicator that shows the value of the services and products produced by a country usually in a one year period.
What is the difference between real and nominal GDP?In general real GDP is considered to be more accurate as nominal GDP is influenced by factors such as inflation that can distort the general idea you can get about a country's economy and the total output of it.
What do economic indicators reveal?Both real, nominal GDP and other indicators show the health of the economy in a country, which makes it useful to draw conclusions about the economy.
Learn more about GDP in: https://brainly.com/question/15899184
#SPJ1
Suppose that the function h is defined, for all real numbers, as follows.
=hx +−12x24 ≠if x2
−2 =if x2
Find h−3, h2, and h4.
The function h is defined, for all real numbers h(-3) = -1/2 , h(2) = -2 and h(4) = -4.
What is a function ?
When it comes to arithmetic, a function is represented as a rule that produces a different result for each input x. Mathematicians refer to functions as mapping or transformations.
The given function,
h(x) = -1/2 x^2 + 4 if x≠ 2
-2 if x=2
So, h(-3) = -1/2 (-3)^2 + 4
= - 9/2 + 4
= -1/2
h(2) = -2 ( given )
h(4) = -1/2 (4)^2 + 4
= -8 + 4
= -4 .
Learn more about functions from the link given below:
https://brainly.com/question/25638609
#SPJ1
In 1950, a U.S. population
model
was y = 151. (1.013)^t-1950 million
people, where t is the year. What did
the model predict the U.S. population
would be in the year 2000?
In a case whereby In 1950, a U.S. population model was y = 151. (1.013)^t-1950 million people, where t is the year, the model predict the U.S. population would be 288 million in the year 2000.
What is population model ?Population models are mechanical theories that link alterations in population structure and density to responses at the individual level (life history features in eco-evolutionary theory or vital rates in demographic theory).
The model was given as y=151x(1.013)^t-1950
where the future time t = 2000
Then we can substitute the given year 2000 as the value of 't'
then we will have y=[151x(1.013)^(2000-1950)] = 288 million
Learn more about model at:
https://brainly.com/question/24448358
#SPJ1
is it correct? i will brinlist to who answer first
I don't see the full picture but your answer should look like this:
4ab+(-12ab)+9ab+(-5ab)
= 4ab-12ab+9ab-5ab
= (4-12+9-5)ab
= -4ab
Please can someone explain this question to me step-by step, i have a exam this Wednesday so pleasee help me!! Help is greatly greatly appreciated ^^
Thankyou!!
Answer:
AB = 45.688 metres
Step-by-step explanation:
* i used a scientific calculator for my working. i am not sure if calculators are permitted for your exam on Wednesday *
⭐AB = AD + DB
⭐AB = 16.5 + DB
Thus, we need to find DB in order to solve for AB.
First, I utilized the triangle sum theorem to find ∠BDC:
[tex]< BDC + < DCB + < B = 180\\ < BDC + 59 + 90 = 180\\ < BDC + 149 = 180\\ < BDC = 31[/tex]
Then, I utilized the linear pair sum to find ∠ADC:
[tex]< ADC + < BDC = 180\\ < ADC + 31 = 180\\ < ADC = 149[/tex]
Next, I utilized the triangle sum theorem to find ∠DAC:
[tex]< DAC + < ADC + < ACD = 180[/tex]
[tex]< DAC + 149 + 10 = 180[/tex]
[tex]< DAC + 159 = 180[/tex]
[tex]< DAC = 21[/tex]
After, I utilized the law of sines to find DC:
[tex]\frac{sin10}{16.5} = \frac{sin21}{DC}[/tex]
[tex]DCsin10 = 16.5sin21[/tex]
[tex]DC = \frac{16.5sin21}{sin10}[/tex]
[tex]DC = 34.052[/tex]
Then, I utilized the sine function to find DB for ΔBDC:
[tex]sin(59) = \frac{DB}{34.052}[/tex]
[tex]34.052sin(59) = DB[/tex]
[tex]29.188 = DB[/tex]
Finally, I substituted DB into our original equation for AB:
[tex]AB = AD + DB[/tex]
[tex]AB = 16.5 + 29.188[/tex]
[tex]AB = 45.688 metres[/tex]
Good luck on your exam on Wednesday! :-)
The height of the pole will be equal to 45 meters.
Trigonometric Identities are equality statements that hold true for all values of the variables in the equation and that use trigonometry functions. There are numerous distinctive trigonometric identities that relate to a triangle's side length and angle.
Given that the angle BCD is 59 and the angle BCA is 69. The height will be calculated as,
tan(59) = BD / BC
BC = BD / tan(59)
BC = 0.6BD
tan(69) = AB / BC
tan(69) = ( 16.5 + BD ) / BC
BC = 0.38( 16.5 + BD )
Equate the values of BC,
0.6BD = 0.38 ( 16.5 + BD )
0.6BD = 6.27 + 0.38BD
0.22BD =6.27
BD = 28.5 meters
The height of the pole is,
AB = AD + DB
AB = 16.5 + 28.5
AB = 45 meters
The height is 45 meters.
To know more about trigonometry follow
https://brainly.com/question/25224151
#SPJ2
What is the exponential form of the expanded form below?
3.3.3.3.3.3.3
3•7
3^7
7^3
3^6
Answer:
Step-by-step explanation:
okay so its 3•7
that's all u need put that
Answer:
[tex]3^{7}[/tex]
Step-by-step explanation:
3×3×3×3×3×3×3= [tex]3^{1+1+1+1+1+1+1+1} =3^{7}[/tex]
3+3+3+3+3+3+3= 3×7
How is 25 to 5 and 10 to 2 equivalent ratios
Answer:
They are equivalent ratios because if you multiply 10 to 2 by 2.5 you get 25 to five
Answer:
equals 25
Step-by-step explanation:
find the indefinite integral and check the result by differentiation. (use c for the constant of integration.) $$ \int \sqrt[3]{{\color{red}3} - {\color{red}4} x^2} ({\color{red}-8} x) \text{ }dx $$
The indefinite integral is - 1 / [5(6 + [tex]x^{5}[/tex])] + C.
An integral is considered to be indefinite if it has no upper or lower bounds. In mathematics, the most generic antiderivative of f(x) is known as an indefinite integral and expressed by the expression f(x) dx = F(x) + C. Without upper and lower bounds on the integrand, indefinite integrals are stated using the notation f(x), which represents the function as an antiderivative of F. Consequently, "f(x) dx=F" (x). As we observed in the same example with antiderivatives, the integral, x3 dx=14x4+C, is one example.
The area under the f(x) curve from x=a to x=b is represented by the definite integral of f(x), which is a NUMBER. Integral indefinite. An indefinite integral of a function f(x), also known as an antiderivative, is denoted by and its derivative is denoted by f. (x). The indefinite integral is not the only solution because the derivative of a constant is zero. Integration is the action of locating an indefinite integral.
Use a u-substitution with u = (6 + [tex]x^{5}[/tex])
du = 5[tex]x^{4}[/tex]dx
1/5 ∫ [tex]u^{-2}[/tex]du
= -1/5 [tex]u^{-1}[/tex] + C
= - 1 / [5(6 + [tex]x^{5}[/tex])] + C
To learn more about indefinite integral Visit : brainly.com/question/27419605
#SPJ4
Correct Question:
Find the indefinite integral and check the result by differentiation. (Use C for the constant of integration.)
[tex]\int\limits^ {} \frac{x^{4} }{(6+x^{5})^{2} } dx[/tex]
What is the value of sin0 given that (-3,4) is a point on the terminal side of 0?
30-(-2)*(-10)+(-5)-(-2)=
Answer:
Step-by-step explanation:
-2 * -10 = 20
Answer:
30×2×(-10)-5+2
=60×(-10)-3
=-60-3
=-63
Lines PQ and BC are parallel.
What is the value of x ?
Answer:
x = 40
Step-by-step explanation:
since lines PQ and BC are parallel , then
∠ BCQ and ∠ AQP are corresponding angle and are congruent , that is
∠ BCQ = 80°
the sum of the 3 angles in Δ ABC = 180° , then
x + 80 + 60 = 180
x + 140 = 180 ( subtract 140 from both sides )
x = 40
Ida wants to know if males and females prefer different brands of ready-made chocolate-chip cookie dough. She bakes eight dozen cookies from dough made by each of four manufacturers which she labels brands A, B, C, and D. She then selects a simple random sample of 96 students, records their gender, gives them one cookie of each brand and asks which brand they like best. Here are her results:
9. The conditional distribution for preferred cookie brand among males (in percents) is given by which of the following?
A. A: 27%; B: 19%; C: 25%; D: 29%
B. A: 4%; B: 6%; C: 13%; D: 15%
C. A: 11%; B: 16%; C: 34%; D: 39%
D. A: 23%; B: 13%; C: 11%; D: 14%
E. A: 38%; B: 21%; C: 19%; D: 22%
They like best brand C) A: 11%; B: 16%; C: 34%; D: 39%.
What is probability ?
Probability is simply how likely something is to happen. Whenever we're unsure about the outcome of an event, we can talk about the probabilities of certain outcomes—how likely they are. The analysis of events governed by probability is called statistics.
Have given ,
Ida made four brands A , B , C and D
Mostly students like A brand 11% , B brand 16% , C brand 34% and D brand 39%
So this is best brand like by students male and female
They like best brand C) A: 11%; B: 16%; C: 34%; D: 39%.
To learn more about probability visit : brainly.com/question/30034780
#SPJ4
Image below to be answered
a.The formula that describe the sequence or progression is a+(7-7n)
b. 2nd term = -10 , 3rd term = 10, 4th term = -10 and 5th term = 10
What is arithmetic and geometric progression?Geometric Progression (GP) is a type of sequence where each succeeding term is produced by multiplying each preceding term by a fixed number, which is called a common ratio.
Arithmetic Progression (AP) is a sequence of numbers in order, in which the difference between any two consecutive numbers is a constant value. It is also called Arithmetic Sequence.
The nth term of an arithmetic progression is given as a(n)= a + (n − 1) × d
In geometric progression the nth term is given as a(n)= ar^(n-1)
where a is the first term
therefore if a = 12 and d is - 7
the formula for the arithmetic progression =
a(n) = 12+(n-1) -7 = 12+( 7-7n)
If the first term of a GP is 10 with common ratio of -1
then the second term = 10×-1 = -10
third term = -10×-1 = 10
fourth term = 10×-1 = -10
fifth term = -10× -1 = 10
learn more about Arithmetic and geometric progression from
https://brainly.com/question/24643676
#SPJ1
Of all the fish in a certain river, 20 percent are salmon. Once a year, people can purchase a fishing license that allows them to catch up to 8 fish. Assume each catch is independent. Which of the following represents the probability of needing to catch 8 fish to get the first salmon? A. 0.2 B 1/0.2 C. 0.2^8 D 0.2 (0.8)^7
E. 0.8 (0.2)^7
The probability of needing to catch 8 fish to get the first salmon is D) 0.2 (0.8)^7.
How to calculate probability of needing to catch 8 fish to get the first salmon?
Given that he probability of fishing a salmon in a certain river is 20% i.e. 0.2. Now, the probability of not getting a salmon will be
1 - probability of not getting salmon = 1 - 0.2 = 0.8.
So, the first fish should be salmon and the others should not be salmon. So, the required probability of independent events can be calculated as,
P =0.2×0.8×0.8×0.8×0.8×0.8×0.8×0.8×0.8
P = 0.2× (0.8)^7
Hence,the probability of needing to catch 8 fish to get the first salmon is 0.2 (0.8)^7.
The probability of needing to catch 8 fish to get the first salmon is D) 0.2 (0.8)^7.
To know more about probability, check out:
brainly.com/question/25870256
#SPJ4
When constructing a confidence interval for a population mean μ from a sample of size 12, the number of degrees of freedom for the critical value tα/2 is ___________________________.
b. Find the critical value tα/2 needed to construct a confidence interval of the given confidence level 90% with sample size 23
When constructing a confidence interval for a population mean the Degrees of freedom is 11 and critical value is 1.717
Degrees of freedom = df = n - 1 =12 - 1 = 11
At 90% confidence level the t is ,
α = 1 - 90% = 1 - 0.90 = 0.1
α / 2 = 0.1 / 2 = 0.05
tα /2, df = t0.05,22 = 1.717 ( using student t table)
The level of confidence denotes the likelihood that the position of a statistical parameter (such as an arithmetic mean) in a sample survey is also true for the population.
A critical value is the test statistic's value that establishes a confidence interval's upper and lower boundaries or a test statistic's threshold for statistical significance.
To learn more about the critical value
https://brainly.com/question/14508634
#SPJ4
need help with all these
Answer:
|
|
|
∆∆∆∆∆∆∆∆∆∆∆∆∆∆
Step-by-step explanation:
get better
May someone help me with this?
Step-by-step explanation:
0 hours -> $500 total cost
1 hour -> $575 total cost (500 + 1×75)
2 hours -> $650 total cost (500 + 2×75)
3 hours -> $725 total cost (500 + 3×75)
P(t) = 75t + 500
Martha has a $200 deductible and 20% co-payment on her health
insurance. Last year she had $6,500 in medical bills. What was
Martha's out-of-pocket expense?
Answer:
Step-by-step explanation:
To solve this problem, we need to calculate Martha's out-of-pocket expenses, and the total amount of money she had to pay for her medical bills.
First, we need to calculate the amount of money Martha had to pay toward her deductible. Since her deductible is $200, this is the amount she had to pay out of pocket.
Next, we need to calculate the amount of money Martha had to pay toward her co-payment. Since her co-payment is 20%, we can calculate this by multiplying her medical bills by the co-payment rate: $6,500 x 0.2 = $1,300.
To find Martha's total out-of-pocket expense, we can add the amount she paid towards her deductible ($200) and the amount she paid towards her co-payment ($1,300):
$200 + $1,300 = $1,500
Therefore, Martha's out-of-pocket expense was $1,500.
Martha's insurance required her to pay a $200 deductible and a 20% co-payment on the remaining balance of her medical bills. After paying the deductible, she pays 20% of the remaining $6,300 which is $1,260. So, Martha's total out-of-pocket expense was $1,460.
Explanation:Martha's health insurance plan includes a $200 deductible and a 20% co-payment. The deductible is the amount Martha has to pay before the insurance company starts to pay. In this case, Martha first pays a $200 deductible from her $6,500 medical bills, which leaves her with $6,300 to be covered by insurance and her co-payment. The 20% co-payment means Martha is responsible for paying 20% of the remaining $6,300. To calculate this, we multiply $6,300 by 0.20 (20%), which equals $1,260. Therefore, Martha's total out-of-pocket expense for her medical bills last year was the $200 deductible plus the $1,260 co-payment, equalling $1,460.
Learn more about Deductibles and Co-payments here:https://brainly.com/question/36325779
#SPJ2
I need help asap i don’t get it
∠SWV is congruent to ∠TWU because vertically opposite angle.
Define congruent.If one of the geometric figures can be superimposed on the other so that their entire surface coincides, then the two are said to be congruent, or to be in the relation of congruence. Two triangles are said to be congruent if their two sides and their included angle are the same in both of them. Congruence appears to be based on the concept of a "rigid body," which may be transported from one location to another without affecting the internal relationships between its components.
Given
∠SWV ≅ ∠TWU
Vertically opposite angle
∠SWV is congruent to ∠TWU because vertically opposite angle.
To learn more about congruent, visit:
https://brainly.com/question/7888063
#SPJ1
the purpose of a check sheet is to quickly understand the primary sources of a problem using the 80/20 rule, wherein 80 percent of defects often come from only about 20 percent of all the sources.
Based on the following question the primary sources of a problem using the 80/20 rule, wherein 80 percent of defects often come from only about 20 percent of all the sources is false
What is 80/20 rule?
Only 20% of causes result in 80% of all consequences, according to the 80/20 rule. It is used to pinpoint the crucial elements of success (often in a corporate context) and concentrate efforts therein to enhance outcomes.
What is the 80-20 rule in life?According to the 80-20 rule, 20% of activities produce 80% of the consequences. Or, to put it another way, just 20% of the input results in 80% of the outcome. An old proverb that promotes focus is the 80-20 rule, often known as the Pareto Principle.
To know more about 80/20 rule visit:
https://brainly.com/question/14309471
#SPJ4
If the opposite corners of the rectangle ABCD are A (5, 3) and C (10, 1) and the equation of side BC is x-2y=8, find the equations of the other three sides. You must show your work and explain why you are doing it. (Note: opposite side of a rectangle are parallel and consecutive sides are
perpendicular)
Answer:
Equation of side AB:
We know the coordinates of A and B, so we can use the point-slope form to create the equation of the line:
y - 3 = (3/5)(x - 5)
y - 3 = 3/5x - 15/5
5/3y - 15/3 = x - 5
5/3y - x = -15/3 + 5
5/3y - x + 15/3 = 5
5/3y - x + 15/3 = 0
Equation of side AB: 5/3y - x + 15/3 = 0
Equation of side DC:
We know the coordinates of C and D, so we can use the point-slope form to create the equation of the line:
y - 1 = (2/5)(x - 10)
y - 1 = 2/5x - 20/5
5/2y - 10 = x - 10
5/2y - x = -10
5/2y - x - 10 = 0
Equation of side DC: 5/2y - x - 10 = 0
Equation of side BD:
We know the equation of side BC (x - 2y = 8) and that consecutive sides are perpendicular, so we can use the slope-intercept form to find the equation of line BD:
Slope of BC = -2/1
Slope of BD = -1/-2 = 1/2
y = (1/2)x + b
We can use the coordinates of B to find b:
1 = (1/2)(8) + b
2 = 4 + b
b = -2
Equation of side BD: y = (1/2)x - 2
Step-by-step explanation:
I need help with the statement and the reasons
Explanation:
You can make use of the properties of parallel lines to prove ∠ACB≅∠DAC.
Statement . . . . Reason
2. ∠DAB +∠ABC = 180° . . . . definition of a right angle
3. AD║BC . . . . consecutive interior angles are supplementary
4. ∠ACB≅∠DAC . . . . alternate interior angles are congruent