Question

What is the measure of angle A?

Select the best answer from the choices provided.
A.26°
B.32°
C.64°
D.78°

Answer 1

C

Explanation:

The sum of the 3 angles in a triangle = 180° , so

7x + 8 + 3x + 2 + 90 = 180 , that is

10x + 100 = 180 ( subtract 100 from both sides )

10x = 80 ( divide both sides by 10 )

x = 8

Then

∠ A = 7x + 8 = 7(8) + 8 = 56 + 8 = 64° → C

Answer 2

Angle B is 90 degrees so angle A and c when added also equal 90:

7x + 8 + 3x + 2 = 90

Simplify:

10x + 10 = 90

Subtract 10 from both sides

10x = 80

Divide both sides by 10

X = 8

Now you have x calculate angle A:

7x + 8 = 7(8) + 8 = 56 + 8 = 64

Answer: C. 64