TED-Ed

View full lesson: http://ed.ted.com/lessons/euclid-s-puzzling-parallel-postulate-jeff-dekofsky Euclid, known as the "Father of Geometry," developed several of modern geometry's most enduring theorems--but what can we make of his mysterious fifth postulate, the parallel postulate? Jeff Dekofsky shows us how mathematical minds have put the postulate to the test and led to larger questions of how we understand mathematical principles. Lesson by Jeff Dekofsky, animation by The Leading Sheep Studios.