Thanks to @RokCoder for sharing this puzzle, and of course @kriblos_test for the demo project. Click anywhere for the Next Slide One right angled triangle. Each side of the triangle is a diameter of one of the circles. The shaded region R is the region inside the two smaller circles but outside the largest circle. Prove that the area of R is equal to the area of the triangle.
I just took @kriblo_test's thumbnail and used it to make a simple 4 slide slideshow demonstrating my Proof, which doesn't require any calculations, just observations and a very well known theorem.
