Si a2 - b2 = 7 (a + b), entonces a - b =

Which statements are true? see picture

Alex 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 80 degrees.

Pranza plotted point a in the coordinate plane below.