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

Question

Accepted Answer

Step 1: Let AB be the chord of the larger circle touching the smaller circle at P. $OA = 5$ cm, $OP = 3$ cm. $OP \perp AB$ (radius $\perp$ tangent).
Step 2: In right-angled $	riangle OAP$: $AP^2 = OA^2 - OP^2 = 5^2 - 3^2 = 16 \Rightarrow AP = 4$ cm
Step 3: $AB = 2 	imes AP = 2 	imes 4 = 8$ cm

Question

Solution