Answer:
∠Q = 75 °
Explanation:
Since PR = PQ then Δ PQR is isosceles and the base angles are congruent, that is
∠R = ∠Q = 2x + 15
The sum of the 3 angles in a triangle = 180°
Sum the 3 angles and equate to 180
2x + 15 + 2x + 15 + x = 180, that is
5x + 30 = 180 ( subtract 30 from both sides )
5x = 150 ( divide both sides by 5 )
x = 30
Hence
∠Q = 2x + 15 = (2 × 30) + 15 = 60 + 15 = 75°