Geometry Mathley 1.4 concurrency of 4 lines
Source:
June 6, 2020
concurrentgeometrycirclestangent circles
Problem Statement
Given are three circles , pairwise intersecting each other, that is, every single circle meets the other two circles at two distinct points. Let be the circle externally tangent to and internally tangent to the circles circles are defined in the same manner. Let be the circle internally tangent to and externally tangent to the circles , the circles are defined in the same way. Let be two circles internally tangent to all three circles . Prove that the four lines are concurrent.Nguyễn Văn Linh