MathDB

An exterior common tangent to two non-intersecting circles with centers and

O_2

touches them at the points

A_1

and

A_2

respectively. The segment

O_1O_2

intersects the circles at the points

B_1

and

B_2

respectively.

C

is the point where the straight lines

A_1B_1

and

A_2B_2

meet.

D

is the point on the line

A_1A_2

such that

CD

is perpendicular to

B_1B_2

. Prove that

A_1D = DA_2

Problem Statement