In the regular pentagon $ABCDE$, the perpendicular at $C$ to $CD$ meets $AB$ at $F$. Prove that $AE+AF=BE$. Proposed by Alireza Cheraghi
Source: 4th Iranian Geometry Olympiad (Elementary) P3
Tags: IGO, Iran, geometry
In the regular pentagon $ABCDE$, the perpendicular at $C$ to $CD$ meets $AB$ at $F$. Prove that $AE+AF=BE$. Proposed by Alireza Cheraghi