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

Explanation

Let `AB` be the chord , `P` be the point where it touches the smaller circle and `O` be the common centre.
`AB` is tangent to smaller circle and so, `OPbotAB`.
`:.P` is the midpoint of `AB`, i.e., `AP=PB`. [`:` a perpendicular from the centre on may chord bisects the chord].
Now, `OP=3cm`, `OQ=5cmimpliesAP=sqrt(OA^(2)-OP^(2))=sqrt(5^(2)-3^(2))=4`.
`:.AB=2AP=8cm`.