This Is a Certified Answer

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
ABCDE be a regular pentagon.  AE be base. C be the top vertex from which a perpendicular is drawn to AE meeting AE at F.  So AFC and CFE are right angle triangles.  AC and EC are same as it is a regular pentagon. In these two triangles two sides are equal AC = EC and CE =CE. Angle CFA and CFE = 90.  So they rare congruent. AF = EF.