2009 ToT Spring Junior A P7 sum of triangle areas
Source:
February 26, 2020
isoscelesgeometryareas
Problem Statement
Angle of an isosceles triangle equals . Each of two rays emitting from vertex (inwards the triangle) meets at some point () reflects according to the rule the angle of incidence equals the angle of reflection" and meets lateral side of triangle at point (). Given that angle between the rays equals , prove that area of triangle equals the sum of areas of triangles and ().