Answer:
dL/dt = - 2,019 m/h
Step-by-step explanation:
L² = x² + y² (1) Where x, and y are the legs of the right triangle and L the hypotenuse
If the base of the triangle, let´s call x is increasing at the rate of 2 m/h
then dx/dt = 2 m/h. And the height is decreasing at the rate of 3 m/h or dy/dt = - 3 m/h
If we take differentials on both sides of the equation (1)
2*L*dL/dt = 2*x*dx/dt + 2*y*dy/dt
L*dL/dt = x*dx/dt + y*dy/dt (2)
When the base is 9 and the height is 22 according to equation (1) the hypotenuse is:
L = √ (9)² + (22)² ⇒ L = √565 ⇒ L = 23,77
Therefore we got all the information to get dL/dt .
L*dL/dt = x*dx/dt + y*dy/dt
23,77 * dL/dt = 9*2 + 22* ( - 3)
dL/dt = ( 18 - 66 ) / 23,77
dL/dt = - 2,019 m/h
Using implicit differentiation and the Pythagorean Theorem, it is found that the hypotenuse is changing at a rate of -2.02 meters per hour.
The Pythagorean Theorem states that the square of the hypotenuse h is the sum of the squares of the base x and of the height h, hence:
[tex]h^2 = x^2 + y^2[/tex]
In this problem, [tex]x = 9, y = 22[/tex], hence, the hypotenuse is:
[tex]h^2 = 9^2 + 22^2[/tex]
[tex]h = \sqrt{9^2 + 22^2}[/tex]
[tex]h = 23.77[/tex]
Applying implicit differentiation, the rate of change is given by:
[tex]2h\frac{dh}{dt} = 2x\frac{dx}{dt} + 2y\frac{dy}{dt}[/tex]
Simplifying by 2:
[tex]h\frac{dh}{dt} = x\frac{dx}{dt} + y\frac{dy}{dt}[/tex]
The rates of change given are: [tex]\frac{dx}{dt} = 2, \frac{dy}{dt} = -3[/tex].
We want to find [tex]\frac{dh}{dt}[/tex], hence:
[tex]h\frac{dh}{dt} = x\frac{dx}{dt} + y\frac{dy}{dt}[/tex]
[tex]23.77\frac{dh}{dt} = 9(2) + 22(-3)[/tex]
[tex]\frac{dh}{dt} = \frac{18 - 66}{23.77}[/tex]
[tex]\frac{dh}{dt} = -2.02[/tex]
The hypotenuse is changing at a rate of -2.02 meters per hour.
A similar problem is given at https://brainly.com/question/19954153
A truck costs $8,000 with a residual value of $1,000. It has an estimated useful life of 7 years. If the truck was bought on July 9 what would be the book value at the end of year 1?
Answer:
$7520.55
Step-by-step explanation:
Cost of truck = $8000
Residual value = $1000
Estimated useful life = 7 years
Depreciation = (cost of asset - salvage value) / useful life
Depreciation = (8000 - 1000) / 7
Depreciation = 7000 / 7
Depreciation = $1000
Truck was purchased on July 9, Therefore, Depreciation by the end of year one will be;
Number of days between July 9 and year end = 175 days
Daily Depreciation = $1000 / 365 = $2.739
Total Depreciation by year end = (daily Depreciation * 175 days) = $479.45.
Book value at the end of year 1 = (8000 - 479.45)
= $7520.55
Answer:
The answer is "$7,500".
Step-by-step explanation:
Formula:
In the month of July-December the depreciation:
[tex]\frac{\text{Cost-Residual}}{\text{Useful life}}\times \frac{6}{12} \\[/tex]
Cost-Residual= costs -residual value
Given:
Cost-Residual = $8, 000 - $ 1,00
= $7,000
Useful life= 7 years
Put the value in the above-given formula:
[tex]=\frac{7 000}{7}\times \frac{6}{12}\\\\= 1 000\times \frac{1}{2}\\\\= 5 00\\[/tex]
Therefore, the book value on point at the end of one year is:
= $8,000 -$ 500
= $7,500
Fill in the blank with a number to make the expression a perfect square.
u^2+8u+?
Answer:
16
Step-by-step explanation:
Hello, do you remember that result?
For any a and b real numbers,
[tex](a+b)^2=a+2\cdot a \cdot b+b^2[/tex]
In this example, we have.
[tex]u^2+8u=u^2+2\cdot 4 \cdot u\\\\\text{ This is the beginning of ... } u^2+8u+4^2=u^2+8u+16\\\\\text{ So, we need to add 16 to make a perfect square}\\\\u^2+8u+\boxed{16}=u^2+2\cdot 4\cdot u +4^2=(u+4)^2[/tex]
Hope this helps.
Do not hesitate if you need further explanation.
Thank you
I answered all my work correctly but I don’t understand this one.
James conducted an experiment with 4 possible outcomes. He determined that the experimental probability of event A happening is 10 out of 50. The theoretical probability of event A happening is 1 out of 4. Which action is most likely to cause the experimental probability and theoretical probabilities for each event in the experiment to become closer? removing the last 10 trials from the experimental data completing the experiment many more times and combining the results to the trials already done including a fifth possible outcome performing the experiment again, stopping immediately after each event occurs once
Answer:
Completing the experiment a few more times and combining the results to the trails already done.
Answer:
Completing the experiment a few more times and combining the results to the trails already done.
Step-by-step explanation:
. Find two polynomial expressions whose quotient, when simplified, is 1/x . Use that division problem to determine whether polynomials are closed under division.
Answer:
The two polynomials are:
(x + 1) and (x² + x)
Step-by-step explanation:
A polynomial is simply an expression which consists of variables & coefficients involving only the operations of addition, subtraction, multiplication, and non - negative integer exponents of variables.
Now, 1 and x are both polynomials. Thus; 1/x is already a quotient of a polynomial.
Now, to get two polynomial expressions whose quotient, when simplified, is 1/x, we will just multiply the numerator and denominator by the same polynomial to get more quotients.
So,
Let's multiply both numerator and denominator by (x + 1) to get;
(x + 1)/(x(x + 1))
This gives; (x + 1)/(x² + x)
Now, 1 and x are both polynomials but the expression "1/x" is not a polynomial but a quotient and thus polynomials are not closed under division.
Sam ran 63,756 feet in 70 minutes. What is Sam's rate in
miles per hour? (There are 5,280 feet in one mile.)
Step 1: What is Sam's rate as stated?
63,756 feet
63, 756 ft
70 min
70 minutes
Step 2: What factor is used to convert feet per minute into
miles per minute?
Step 3: what factor is used to convert miles per minute to miles per hour
Answer:
10.35 miles per hour
Sam's rate as stated is 63,756 feet per 70 minutes
Divide by 5,280 feet
Divide by 60 minutes
Step-by-step explanation:
1. Find how many feet Sam ran in one minute
63,756 ÷ 70 = 910.8 ft.
2. Find how many feet he ran in one hour
910.8 · 60 = 54,648 ft.
3. Convert the feet to miles
54,648 ÷ 5280 = 10.35
Step 2: There are 5280 feet in one mile. Therefore, you would divide by 5280 feet to convert feet per minute into miles per minute.
Step 3: There are 60 minutes in one hour. Therefore, you would divide by 60 minutes to convert miles per minute to miles per hour.
Answer:
1: 63,756 and 70 mins
2: 1 mile and 5,280 feet
3: 60 mins and 1 hour
4: 10.35
HELP ASAP PLEASE!!!!!!!!!!!!!!!!!
Answer:
A
C
D
Step-by-step explanation:
√54 or√9 *√6 or √27 *√4
are equal to the answer.
You can do that by doing the square of outer number which is 3 which equals to 9 when squared and multiplying that with the number inside the square root.
What is the perimeter of the figure shown?
Answer:
[tex]\boxed{16 units}[/tex]
Step-by-step explanation:
Hey there!
Well since all the sides are congruent and there are 8 sides we can make the following expression,
P = 2*8
P = 16
Hope this helps :)
Answer:
16
Step-by-step explanation:
The sides of this figure are equal to each other .
the permiter is the sum of the sides
The figure has 8 sides.
● P = 8 × 2
● P = 16
1)Sheyna drive to the lake and back. It took two hours less time to get there than it did to get back. The average speed on the trip there was 60 mph. The average speed on the way back was 36 mph. How many hours did the trip there take?
Answer:
8 hours
Step-by-step explanation:
Given:
Sheyna drives to the lake with average speed of 60 mph and
[tex]v_1 = 60\ mph[/tex]
Sheyna drives back from the lake with average speed of 36 mph
[tex]v_2 = 36\ mph[/tex]
It took 2 hours less time to get there than it did to get back.
Let [tex]t_1[/tex] be the time taken to drive to lake.
Let [tex]t_2[/tex] be the time taken to drive back from lake.
[tex]t_2-t_1 = 2[/tex] hrs ..... (1)
To find:
Total time taken = ?
[tex]t_1+t_2 = ?[/tex]
Solution:
Let D be the distance to lake.
Formula for time is given as:
[tex]Time =\dfrac{Distance}{Speed }[/tex]
[tex]t_1 = \dfrac{D}{60}\ hrs[/tex]
[tex]t_2 = \dfrac{D}{36}\ hrs[/tex]
Putting in equation (1):
[tex]\dfrac{D}{36}-\dfrac{D}{60} = 2\\\Rightarrow \dfrac{5D-3D}{180} = 2\\\Rightarrow \dfrac{2D}{180} = 2\\\Rightarrow D = 180\ miles[/tex]
So,
[tex]t_1 = \dfrac{180}{60}\ hrs = 3 \ hrs[/tex]
[tex]t_2 = \dfrac{180}{36}\ hrs = 5\ hrs[/tex]
So, the answer is:
[tex]t_1+t_2 = \bold{8\ hrs}[/tex]
1. In a right triangle, the lengths of the legs are a and b. Find the length of a hypotenuse, if: a=1, b=1; 2. In a right triangle, the length of a hypotenuse is c and the length of one leg is a. Find the length of the other leg, if: c=5, a=3;
Answer:
1. [tex]c = \sqrt{2}[/tex].
2. b = 4.
Step-by-step explanation:
To solve these two questions, keep the Pythagorean Theorem in mind: [tex]a^2 + b^2 = c^2[/tex]. Also remember that measurements cannot be negative, so we will disregard the negative answers.
1. a = 1, and b = 1. c = ?
[tex]1^2 + 1^2 = c^2[/tex]
[tex]1 + 1 = c^2\\[/tex]
[tex]c^2 = 1 + 1\\c^2 = 2\\\sqrt{c^2} = \sqrt{2}\\c = \sqrt{2}[/tex]
2. a = 3, c = 5. b = ?
[tex]3^2 + b^2 = 5^2\\9 + b^2 = 25\\b^2 = 16\\\sqrt{b^2} = \sqrt{16}\\b = 4[/tex]
Hope this helps!
Type the correct answer in the box. Use numerals instead of words. If necessary, use / for the fraction bar. Stacy goes to the county fair with her friends. The total cost of ride tickets is given by the equation c = 3.5t, where c is the total cost of tickets and t is the number of tickets. If Stacy bought 15 tickets, she would spend $
Answer:
$52.2Step-by-step explanation:
Given her total cost of ride tickets modeled by the equation c = 3.5t where c is the total cost of tickets and t is the number of tickets, If Stacy bought 15 tickets, to know the amount she would spend on 15 tickets, we will substitute t = 15 into the modeled equation as shown;
[tex]c = 3.5t\\when t = 15\\\\c = 3.5(15)\\\\c = \frac{35}{10} * 15\\ \\c = \frac{5*7}{5*2} * 15\\\\[/tex]
[tex]c = \frac{7}{2} * 15\\ \\c = \frac{105}{2}\\ \\c = \ 52.2[/tex]
Hence Stacy would spend $52.2 on 15 tickets
Answer:
I hope this helps!
Step-by-step explanation:
A shop sells DVDs and CDs.
DVDs are sold at one price.
CDs are sold at a different price.
2 DVDs and 1 CD cost £35
2 DVDs and 2 CDs cost £45
Martin has £50 Does he have enough to buy 1 DVD and 3 CDs?
Answer:
Step-by-step explanation:
Lets Price of a DVD is fixed i.e. 15
and One CD price is 5 (Not fixed)
In First situation
2 DVDs and 1 CD cost = 35 as given
2 x 15 + 5 = 35
Lets one CD price is 7.5
In Second situation
2 x 15 + 2 x 7.5 = 45
Its mean CD price may be between 5 to 7.5
In asked scenario, Martin has 50
1 DVD and 3 CDs?
1 x 15 + 3 x 7.5 = 37.5
37.5 is lesser than 50
Hence Martin has enough to buy 1 DVD and 3 CDs.
What is 12.5% of 72
Answer:
[tex]\boxed{9}[/tex]
Step-by-step explanation:
[tex]\sf of \ refers \ to \ multiplication.[/tex]
[tex]12.5\% \times 72[/tex]
[tex]\frac{12.5}{100} \times 72[/tex]
[tex]\sf Multiply.[/tex]
[tex]\frac{900}{100} =9[/tex]
A laundry basket contains 18 blue socks and 24 black socks. What is the probability of randomly picking 2 black socks, with replacement, from the basket?
Answer:
144/441
Step-by-step explanation:
There are 18+24=42 total socks
There are 24 black socks
So the probability is (24/42)*(24/42)=12/21 * 12/21 = 144/441
Answer:
189
Step-by-step explanation:
LCM of x<sup>2</sup>+5x+6 and x<sup>2</sup>-x-6 is ………………………
Answer:
[tex] (x^2 - 9)(x + 2) [/tex]
Step-by-step explanation:
Given:
[tex] x^2 + 5x + 6 [/tex]
[tex] x^2 - x - 6 [/tex]
Required:
LCM of the polynomials
SOLUTION:
Step 1: Factorise each polynomial
[tex] x^2 + 5x + 6 [/tex]
[tex] x^2 + 3x + 2x + 6 [/tex]
[tex] (x^2 + 3x) + (2x + 6) [/tex]
[tex] x(x + 3) + 2(x + 3) [/tex]
[tex] (x + 2)(x + 3) [/tex]
[tex] x^2 - x - 6 [/tex]
[tex] x^2 - 3x +2x - 6 [/tex]
[tex] x(x - 3) + 2(x - 3) [/tex]
[tex] (x + 2)(x - 3) [/tex]
Step 2: find the product of each factor that is common in both polynomials.
We have the following,
[tex] x^2 + 5x + 6 = (x + 2)(x + 3) [/tex]
[tex] x^2 - x - 6 = (x + 2)(x - 3) [/tex]
The common factors would be: =>
[tex] (x + 2) [/tex] (this is common in both polynomials, so we would take just one of them as a factor.
[tex] (x + 3) [/tex] and,
[tex] (x - 3) [/tex]
Their product = [tex] (x - 3)(x + 3)(x +2) = (x^2 - 9)(x + 2) [/tex]
Remember, a percent is a fractional part
of 100. In a bag of candy, 15 of the 50
pieces are red. What percentage of the
candy is red?
mex
B 50%.
C 3006
D 659
Answer:
Step-by-step explanation:
B
Answer:
The answer would be 30% (although I don't see that as an answer).
Step-by-step explanation:
This is because when you multiply the denominator times a number that makes the denominator 100 and multiply that same number by the numerator you get the percentage of the sample you are looking at on the numerator.
15/50 = (15*2)/(50*2) = 30/100 = 30%
Please Answer THIS QUESTION ASAP ty!! First 2 answer right is BRAINLESS
Hi there! :)
Answer:
[tex]\huge\boxed{A = 119.44 cm^{2} }[/tex]
To find the area of the shaded region, we will need to find the areas of both the rectangle and the circle:
Rectangle: A = l × w
A = 11 × 12
A = 132 cm²
Circle: A = πr² (Let π = 3.14)
A = π(2)²
A = 4π
A ≈12.56 cm²
Subtract the area of the circle from the area of the rectangle:
132 - 12.56 = 119.44 cm².
1.Solve by factorization method: x+1/x=11 1/11 2.Comment on the nature of roots for 4x^2-5=2(〖x+1)〗^2-7 plz, help...
Answer:
The equation
[tex]4\,x^2-5=2\,(x+1)^2-7[/tex]
can be solved by first expanding all indicated operations, and later when the constant terms disappear, by factoring out 2x , leaving the equation as a product of two factors equal zero, from which it is easy to extract the roots. See below.
Step-by-step explanation:
When solving for x in the following expression, and using factoring to apply at the end the zero product theorem:
[tex]4\,x^2-5=2\,(x+1)^2-7\\4\,x^2-5=2\,(x^2+2x+1)-7\\4\,x^2-5=2\,x^2+4\,x+2-7\\4\,x^2-5=2\.x^2+4\,x-5\\4\,x^2=2\,x^2+4\,x\\4\,x^2-2\,x^2-4\,x=0\\2\,x^2-4\,x=0\\2\,x\,(x-2)=0[/tex]
We observe that for the last product, to get a zero, x has to be zero (making the first factor zero), or x has to be "2" making the binomial factor zero.
An average person's hair grows at a rate of 19cm per year how fast in inches per month does the average person hair grow in conversion factor round you answer to the nearest tenths
Answer:
Around 1.6 cm per month
Step-by-step explanation:
We can set up a proportion to find how much the hair grows per month. It's important to note that there are 12 months in a year, so we can represent a year as 12 months.
[tex]\frac{19}{12} = \frac{x}{1}[/tex]
We can now cross multiply:
[tex]19\cdot1=19\\\\19\div12=1.58\overline{33}[/tex]
1.58333... rounds to 1.6.
Hope this helped!
20 squared (+5) divided by 100
The answer is 4.05
Step-by-step explanation:
20^2 is 20•20 which is 400 || +5=405 || /100=4.05
Consider the plot created from the residuals of a line of best fit for a set of data.
Does the residual plot show that the line of best fit is appropriate for the data?
Yes, the points have no pattern.
No, the points are evenly distributed about the x-axis.
No, the points are in a linear pattern.
Yes, the points are in a curved pattern.
Answer:
No, the points are in a linear pattern.
Step-by-step explanation:
Residual plot is a graph that shows the residuals on the vertices. The y-axis has residual values and x-axis has independent variables. The horizontal axis shows the independent variables to determine the best fit for a set. The graph given is in a linear pattern. The random pattern shows that linear model is good fit.
Answer:
C: No, the points are in a linear pattern
Step-by-step explanation:
edg2021
I have been seeing this question with multiple different answers, and no one is sure about anything! All I can say for sure is that IT IS NOT A! So C makes the most sense. B is simply not true, and neither is D, its not curved or evenly distribute.
What is the rate of change and initial value for the linear relation that includes the points shown in the table?
ху
1 | 20
3 | 10
5 | 0
7 | -10
A. Initial value: 20, rate of change: 10
B. Initial value: 30, rate of change: 10
C. Initial value: 25, rate of change: -5
D. Initial value: 20, rate of change: -10
Answer:
C, at 0/25, 1/20, 2/15, 3/10,...
Answer:
C
Step-by-step explanation:
At the Olympic games, many events have several rounds of competition. One of these events is the men's 100 100100-meter backstroke. The upper dot plot shows the times (in seconds) of the top 8 88 finishers in the final round of the 2012 20122012 Olympics. The lower dot plot shows the times of the same 8 88 swimmers, but in the semifinal round. Which pieces of information can be gathered from these dot plots? (Remember that lower swim times are faster.) Choose all answers that apply: Choose all answers that apply:
Answer:
The center of the semifinal round distribution is greater than the center of final round distribution.
The variability in the semifinal round distribution is less than variability in the final round distribution.
Step-by-step explanation:
The mean value of each distribution set is not calculates as the center of semifinal round distribution is greater than the final round distribution. MAD Mean Absolute Deviation is calculated from the dotted graph plot, the distribution of semifinal round is less spread out than the final round distribution.
Answer:
correct answer is None of the above i understood nothing the other person was trying to say...
Step-by-step explanation:
mark me brainliest please...
Z= -3 - 8i Find the angle θtheta (in degrees) that z makes in the complex plane. Round your answer, if necessary, to the nearest tenth. Express θtheta between -180 180 degrees.
The angle is negative to indicate a clockwise rotation.
======================================================
Explanation:
Z = -3 - 8i is in the form z = a+bi with a = -3 and b = -8
In the complex plane the point (a,b) represents the location of z = a+bi
Define three points with the locations
P = (a,b) = (-3,8)
Q = (0,0)
R = (10,0)
The angle PQR is the angle theta we're looking for. This is the angle formed between the positive x axis and the terminal point (a,b)
Use the arctan function to find theta
theta = arctan(b/a)
theta = arctan( (-8)/(-3) )
theta = 69.4439547804166
theta = 69.4 degrees approximately
Note how this theta value is in quadrant Q1, but (a,b) = (-3, -8) is in Q3
So we need to add 180 degrees to adjust this error.
69.4+180 = 249.4
and we're now in the proper quadrant. We would stop here if your teacher did not put the restriction that theta must be between -180 and 180.
However, this restriction is in place so we need to find the difference of 360 and 249.4 to get 360-249.4 = 110.6
-----------
The angle 249.4 degrees is coterminal to -110.6 degrees. They both point in the same direction.
angle 249.4 degrees is found by starting pointing directly east and rotating 249.4 degrees counterclockwise
angle -110.6 degrees is found by starting directly east and rotating 110.6 degrees clockwise.
Check out the diagram below. I used GeoGebra to make the diagram.
Basic math for 20 points + brainliest!
Answer:
Look at photo
Step-by-step explanation:
I need help on both answers. They’re different from my other problems so I’m kinda confused
Please solve (will make brainiest)
Answer:
1a) 1/64
1b) 1/169
1c) 1/9
Step-by-step explanation:
You have to apply Indices Law :
[tex] {a}^{ - n} = \frac{1}{ {a}^{n} } [/tex]
Question A,
[tex] {4}^{ - 3} = \frac{1}{ {4}^{3} } = \frac{1}{64} [/tex]
Question B,
[tex] {13}^{ - 2} = \frac{1}{ {13}^{2} } = \frac{1}{169} [/tex]
Question C,
[tex] {( - 3)}^{ - 2} = {( - \frac{1}{3}) }^{2} = \frac{1}{9} [/tex]
There are 9 classes of 25 students each, 4 teachers, and two times as many chaperones as teachers.
Each bus holds a total of 45 people.
What is the least number of buses needed for the field trip?
5 buses is the answer pls mark me brainliest
Least number of bus require for trip = 5 buses
What is Unitary method?It is a method where we find the value of a single unit from the value of multiple units and the value of multiple units from the value of a single unit.
Steps to Use Unitary Method
First, let us make a note of the information we have. There are 5 ice-creams. 5 ice-creams cost $125.
Step 1: Let’s find the cost of 1 ice cream. In order to do that, divide the total cost of ice-creams by the total number of ice-creams. The cost of 1 ice-cream = Total cost of ice-creams/Total number of ice-creams = 125/5 = 25. Therefore, the cost of 1 ice cream is $25.
Step 2: To find the cost of 3 ice-creams, multiply the cost of 1 ice cream by the number of ice-creams. The cost of 3 ice-creams is cost of 1 ice-cream × number of ice-creams = 25 × 3 = $75. Finally, we have the cost of 3 ice-creams i.e. $75.
Given:
Total number of classes = 9
Number of student in each class = 25
Number of teacher = 4
Number of chaperones = Double of teacher
Bus hold = 45 people
Now,
Total number of student = 9 × 25
= 225
Number of chaperones = 4 × 2
= 8
Total people = 225 + 8 + 4
= 237
Least number of bus require for trip = Total people / Bus hold
= 237 / 45
= 5.266
Learn more about unitary method here:
https://brainly.com/question/22056199
#SPJ2
|3x–1|=8 please help!!!!!
Answer: -3
Add 1 to both sides
[tex]3x-1+1=8+1[/tex]
[tex]3x=9[/tex]
Divide both sides by 3
[tex]3x/3=9/3\\x=3[/tex]
1: The best statement for reason 6 of this proof is -∠A ≅ ∠C
-∠B ≅ ∠D
-∠B and ∠D are supplements
-∠B ≅ ∠B
2.The best reason for statements 3.5. and 7 in this proof is
- Alternate interior angles are congruent.
-Corresponding angles are congruent.
-Alternate exterior angles are congruent.
-Interior angles on the same sides of a transversal are supplements.
3. The best statement for reason 8 of this proof is
-∠B ≅ ∠B -∠A and ∠C are supplements.
-∠B ≅ ∠D
-∠A ≅ ∠C
Answer:
1) -∠B ≅ ∠D
2) -Interior angles on the same side of a transversal are supplementary
3) -∠A ≅ ∠C
Step-by-step explanation:
1) Given that ∠A and ∠B are supplements and ∠A and ∠D are supplements, we have; ∠B ≅ ∠D
2) Given that ABCD is a parallelogram, therefore ∠A and ∠B, ∠A and ∠D and ∠B and ∠C are interior angles on the same side of a transversal and are therefore supplementary
3) Given that ∠A and ∠B and ∠B and ∠C are supplementary, therefore, ∠A ≅ ∠C.
