TS _|_ SE if SA = SP and TB = TD
Source: 2th XMO (China) Test 2 p1 https://artofproblemsolving.com/community/c3192772_geometry_regional_china
April 7, 2024
geometryperpendicular
Problem Statement
As shown in the figure, is a diameter of the circumcircle of , and is the midpoint of arc (excluding point ) . The bisector of the exterior angle of intersects and the extension of at point . The ray intersects at point . Point lies on so that . Point lies on such that . Prove that .
https://cdn.artofproblemsolving.com/attachments/c/4/01460565e70b32b29cddb65d92e041bea40b25.png