The figure shows a cyclic quadrilateral ABCD. If E is the incenter of triangle ABC, F the incenter of triangle BCD, G the excenter of triangle ABC, and H the excenter of triangle BCD, prove that EFGH is a rectangle.

Home | Geometry | Search | Problems | All Problems | 601-610 | Quadrilateral | Cyclic Quadrilateral | Email | Post a comment or solution | By Antonio Gutierrez