Question

What is the value of a?
a-470°
a+250°
a-45°
a =

Answer 1

a = 117°

Explanation:

The exterior angle of a triangle = the sum of the remote interior angles.

a + 25° = (a - 47°) + (a - 45°)

a + 25° = (a + a) + (-47 - 45)

a + 25° = 2a - 92°

-2a = -2a

-a +25 = -92

-25 = -25

-a = -117°

a = 117°