3 years ago

In a triangle ABC, AB = 7, AC = 8, BC = 3, what is cos(A)?

1 answer:

6 0

Use the cosine rule.
c=AB=7
b=AC=8
a=BC=3
a^2=b^2+c^2-2bc(cos(A))
=>
cos(A)=(b^2+c^2-a^2)/(2bc)
=(7^2+8^2-3^2)/(2*7*8)
=13/14
=0.9286

You might be interested in

find the area of a circle with a diameter of 4 ft ( Take pi = 3.14 ) round your solution to two decimal places. pls and Hurryyyy

garri49 [273]

Step-by-step explanation:

pi x r^2

3.14 x (2×2) = 12.56

4 0

3 years ago

Read 2 more answers

Explain your answer plez

tiny-mole [99]

Answer:

50°

Step-by-step explanation:

In a parallelogram, opposing angles must be equal. Note how 75° = 75°. Thus, opposing angles 2x + 5 and x + 55 must also be equal.

Solve this equation for x.

Subtracting x from both sides yields x + 5 = 55. Next: Subtracting 5 from both sides yields x = 50° (answer choice C)

8 0

3 years ago

Alex has a price of fabric that is 56 inches long and 3 inches wide. He cuts it into pieces that are each 7 inches long and 1 in

devlian [24]

Each is 7 long and the whole piece is 56 so we can make 8 down the length and each is 1 wide and the whole things is 3 so that makes 3 across. we multiply these to get 8*3= 24

3 0

3 years ago

Given a piece wise<br> function f(x)={2x,x<1 5, x=1

bulgar [2K]

Pretty sure it’s 16TXI, hope this helps!

5 0

3 years ago

Convert 0.888 into a fraction (the 8 is repeating)

Taya2010 [7]

Answer: 8/9

Step-by-step explanation:

0.8888888 = 8/9

7 0

4 years ago