Question

I need help finding x ASAP!!!!

Answer 1

The value of x is 3.

Solution:

Given angles:

m∠D = 9x - 2, m∠C = 40° and ext∠B = 20x + 5

By exterior angle theorem of triangle,

The measure of exterior angle is equal to the sum of the two opposite interior angles.

⇒ ext∠B = m∠D + m∠C

⇒ 20x + 5 = 9x - 2 + 40

⇒ 20x + 5 = 9x + 38

Subtract 5 from both sides.

⇒ 20x = 9x + 33

Subtract 9x from both sides.

⇒ 11x = 33

Divide by 11 on both sides.

⇒ x = 3

The value of x is 3.