Question

6. In adjacent figure, AB & CD are common tangents to two circles of unequal radii. Prove that AB=CD​

Answer 1

Answer:

Just draw another tangent AD.

Now, consider tangents ADandDC.

Since, the lengths of tangents from an external point to a circle is equal  

AD=CD−−−−(i)

Similarly

AD=AB−−−−−(ii)

Now, From (i) and (ii) we get

AB=CD