Question

find the value of b.

Explanation:

Step1: Find an interior - angle

The exterior angle of a triangle is equal to the sum of the two non - adjacent interior angles. Let's first find the interior angle adjacent to the 125° exterior angle. The interior angle and the 125° exterior angle are supplementary. So the interior angle is \(180 - 125=55^{\circ}\).

Step2: Calculate the value of b

We know that the sum of the interior angles of a triangle is 180°. In the triangle, we have one interior angle as 55° and another as 63°. So \(b = 180-(55 + 63)\).
\[b=180 - 118=62\]

Answer:

62