Two circles touch each other internally. Show that the tangents drawn to the 2 circles from any point on the common tangent are equal in length.

Given : AO is a tangent to the circles which intersect each other internally.

Consider the point A,

We construct two tangents AB and AC from point A to the two circles.

Now, AO = AC  [Tangents drawn from an external point to the circle are equal in length]

Also, AB = AO  [Tangents drawn from an external point to the circle are equal in length]

Thus, AB = AC

Hence, tangents drawn to the two circles (touching each other internally) from any point on the common tangent are equal in length.

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