Page 1 of 1

Geomock

Posted: Wed Apr 21, 2021 10:45 pm
by Swapnil Barua
In acute ∆ABC, let AD be the altitude from A on BC. Let P be a point on
AD. Line P B meets AC at E and P C meets AB at F. Suppose that AEDF is concyclic. Prove
that $\frac{P A}{P D}$ = (tanB + tanC)cot($\frac{A}{2}$)