Answer: angle Q = 75 degrees
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The tickmarks on segments PR and PQ indicate they are congruent, ie PR = PQ. Because of this, the base angles R and Q (opposite the segments mentioned) are congruent
Angle R = Angle Q
Since angle R is (2x+15) degrees, so is angle Q
Now use the idea that adding three angles of a triangle leads to 180 degrees
P+Q+R = 180
x+(2x+15)+(2x+15) = 180
5x+30 = 180
5x = 180-30
5x = 150
x = 150/5
x = 30
If x = 30, then angle Q is
angle Q = (2x+15) degrees
angle Q = (2*x+15) degrees
angle Q = (2*30+15) degrees
angle Q = (60+15) degrees
angle Q = 75 degrees