Answer:
∠Q = 75°
Step-by-step explanation:
Start by recognizing that the triangle is isosceles (the long sides are marked as being equal-length). That means angles Q and R have the same measure.
Next, you use the fact that the sum of angles is 180° to write an equation.
∠R +∠P +∠Q = 180°
(2x +15)° +x° +(2x +15)° = 180° . . . . substitute the known values
5x +30 = 180 . . . . . . . . . . . . . . . . divide by °, collect terms
5x = 150 . . . . . . . . subtract 30
x = 30 . . . . . . . divide by 5
Then angle Q is ...
∠Q = (2x +15)° = (2×30 +15)°
∠Q = 75°
