Question

Two circles of same radii r and centres O and O' touch each other at P as shown in Fig. 10.91. If O O' is produced to meet the cirele C (O', r) at A and AT is a tangent to the circle C (O,r) such that O'Q $\perp$ AT. Then AO : AO' =

(a) 3/2

(b) 2

(c) 3

(d) 1/4

Answer 1

From the given figure we have,

AO = r + r + r

AO = 3r

AO’ = r

Therefore,

Also as therefore

Therefore, option (c) is correct.