Triangles on a Rectangle's Diagonal
Triangles made by sliding a point down a rectangle's diagonal are congruent, therefore the smaller rectangles created must have equal area.
1. How do you know that the 2 blue triangles are congruent to each other? The two green triangles are congruent to each other by the same argument. 2. How does that result in pairs of non-congruent rectangles that have equal area?