MathDB
0663 geometry 6th edition Round 6 p3

Source:

May 3, 2021
geometry6th edition

Problem Statement

Let C1,C2C_1, C_2 and C3C_3 be three circles, of radii 2,42, 4 and 66 respectively. It is known that each of them are tangent exteriorly with the other two circles. Let Ω1\Omega_1 and Ω2\Omega_2 be two more circles, each of them tangent to all of the 33 circles above, of radius ω1\omega_1 and ω2\omega_2 respectively. Prove that ω1+ω2=2ω1ω2\omega_1 + \omega_2 = 2\omega_1\omega_2.