Problem: A point P is outside a circle and is 13 inches from the center. A secant from P cuts the circle at Q and R so that the external segment of the secant PQ is 9 inches and QR is 7 inches. The radius of the circle is:
Answer Choices:
A. 3′′
B. 4′′
C. 5′′
D. 6′′
E. 7′′
Solution:
(13+r)(13−r)=16.9∴r2=25,r=5.