2 geometry problems, equal segments, right triangle, semicirle, angle wanted
Source: : Gulf Mathematical Olympiad 2014 p3
August 23, 2019
geometryequal segmentsright trianglesemicircleangle
Problem Statement
(i) is a triangle with a right angle at , and is a point on the hypotenuse .
The line produced beyond meets the line through which is perpendicular to at .
Prove that if, and only if, .
(ii) is a point on the semicircle , and points and are on the line segment .
The line , produced beyond , meets the line through which is perpendicular to at .
Also the line , produced beyond , meets the line through which is perpendicular to at .
Given that and , determine the angle .