Eric examines the strength of a paper chair. Can it actually support the weight of a person? It has long been known that triangles are very strong, but are they really the most powerful forms? Lets go see! It's not magic ... it's mathematical! The pedagogical side: This segment emphasizes the right angle, the right triangle and the equilateral triangle. Triangles are very strong in nature because they create a rigid fixed shape. Triangles have been used in design and architecture for a very long time.