Two concentric circles are of radii and .
Find the length of the chord of the larger circle which touches the smaller circle.
Solve for length of chord:
In and
(radius of same circle)
(given)
(angle made by tangent and radius is )
Therefore, (by RHS congruency criterion)
So, (by C.P.C.T.)
Now, in
(radius of larger circle)
(radius of smaller circle)
(By Pythagoras theorem)
Length of chord
Hence, the length of the chord of the larger circle which touches the smaller circle is .