Math Is Fun Forum

tony123

Member

Registered: 2007-08-03

Posts: 229

collinear points

A, B, C, D are collinear points in this order. Draw the regular triangles ABE and CDF on one side of the line. Let G denote the intersection of the circles ACE and BDF on the same side of the line ABCD. Prove that < AGD=120 °.