two foils overlap on rectangular window 2020-21 Dürer Round1 C3
Source:
December 1, 2022
geometryareasDurer
Problem Statement
Csenge has a yellow and a red foil on her rectangular window which look beautiful in the morning light. Where the two foils overlap, they look orange. The window is cm tall, cm wide and its corners are denoted by and in the figure. The two foils are triangular and both have two of their vertices at the two bottom corners of the window, A and . The third vertex of the yellow foil is , the trisecting point of side closer to , whereas the third vertex of the red foil is , which is one fourth on the way on segment , closer to . The red region (i.e. triangle ) is of area dm. What is the total area of the regions not covered by foil?
https://cdn.artofproblemsolving.com/attachments/b/c/ea371aeafde6968506da6f3456e88fa0bddc6d.png