Gina drew a circle with right triangle prq inscribed in it, as shown below: the figure shows a circle with points p, q, and r on it forming an inscribed triangle. side pq is a chord through the center and angle r is a right angle. arc qr measures 100 degrees. if the measure of arc qr is 100°, what is the measure of angle pqr? a: 65° b: 75° c: 40° d: 50°