MathDB

AP _|_ BP wanted, 2 touchpoints of incircle related

Source: Puerto Rico TST 2023.2.2

March 24, 2024

geometryperpendicularperpendicularity

Problem Statement

Let

I

be the incenter of a triangle

ABC

and let

D

and

E

be the touchpoints of the incircle with sides

BC

and

AC

, respectively. The lines

DE

and

BI

intersect at point

P

. Prove that

AP

is perpendicular to

BP