Question

Find the value of x?
A.45
B.22
C.82
D.56

Answer 1

B

x = 22

Explanation:

2x + 8 + 3x + 5 = 123 (external angle in a triangle = the two opposite angles)

5x = 123 - 13

5x = 110

x = 22

Answer 2

Answer: B

Explanation:

By the Exterior Angle Theorem, we know that the exterior angle is equal to the sum of the two opposite interior angles.

(2x+8)+(3x+5)=123 [combine like terms]

5x+13=123 [subtract both sides by 13]

5x=110 [divide both sides by 5]

x=22

Now, we know that the answer is B.