Question

Two concentric circles are of radii 5 cm and 3 cm. Determine the length of the chord of the larger circle which touches the smaller circle.

Answer 1

Answer: 4

Explanation:

In triangle OCB,

OB2 = OC2 + BC2

52 = 32 + BC2

BC2 = 25 - 9

BC2 = 16

BC = 4