MathDB
right angle wanted, incircle and angle bisector related

Source: Polish second round 1994 p5

January 19, 2020
geometryangle bisectorright angleincircle

Problem Statement

The incircle ω\omega of a triangle ABCABC is tangent to the sides ABAB and BCBC at PP and QQ respectively. The angle bisector at AA meets PQPQ at point SS. Prove ASC=90o\angle ASC = 90^o .