Answer: d. 11.3 cmStep-by-step explanation:The radius of the circle is the length CP, which can be found using the Pythagorean theorem. Since CQ ⊥ PR, you know that Q is the midpoint of PR and PQ = 8 cm.Then the Pythagorean theorem tells you ... CP² = CQ² +PQ² = (8 cm)² + (8 cm)² = 128 cm² CP = √128 cm = 8√2 cm CP = 11.3 cm