9514 1404 393
Answer:
18 cm
Explanation:
Consider right triangle PCA.
The length PC is the hypotenuse of that triangle. It is also the radius of the circle: 15 cm.
The length AC is AB -CB = (27 -15) cm = 12 cm.
The length AP can be found from the Pythagorean theorem:
AP² +AC² = PC²
AP² = PC² -AC² = (15 cm)² -(12 cm)² = (225 -144) cm² = 81 cm²
AP = √(81 cm²) = 9 cm
Since A is the midpoint of PQ, the length of PQ is double the length of AP:
PQ = 2·AP = 2·9 cm
PQ = 18 cm