Question

What's the measure of QPR? ​

Answer 1

∠ QPR = 90°

Explanation:

The exterior angle of a triangle is equal to the sum of the 2 opposite interior angles.

120° is an exterior angle of the triangle , then

∠ QPR + ∠ PQR = 120° , that is

∠ QPR + 30° = 120° ( subtract 30° from both sides )

∠ QPR = 90°