MathDB

3

Part of 1995 Mexico National Olympiad

Problems(1)

collinear points in the regular 7-gon

Source: Mexican Mathematical Olympiad 1995 OMM P3

7/28/2018
A,B,C,DA, B, C, D are consecutive vertices of a regular 77-gon. ALAL and AMAM are tangents to the circle center CC radius CBCB. NN is the intersection point of ACAC and BDBD. Show that L,M,NL, M, N are collinear.
geometryregular polygoncollinear