Question

Find the measure of the missing angle using the exterior angle sum theorm.

Answer 1

`25^(\circ)`

Explanation:

The sum of the interior angles of a triangle is equal to 180 degrees, and each side of a straight line is equal to 180 degrees. Therefore, the exterior angle labelled
`150^(\circ)` must be equal to the sum of the two angles marked
`125^(\circ)` and
`?^(\circ)`:

`125+x=150,\\x=150-125=\boxed{25^(\circ)}`

Thus, the missing angle is
`25^(\circ)`.