c. 300 BCE — today

Three thousand years of the same idea.

c. 300 BCEThe Bride's ChairEuclid of Alexandria · Euclidean AntiquityThe Altitude's ShadowTraditional · Similar triangles AntiquityThe Tilted SquareTraditional · Algebraic AntiquityThe Sliding SquaresTraditional · Dissection AntiquityThe Circle in the CornerTraditional · Other c. 150Four Points on a CircleTraditional · Euclidean c. 263Out and Back InLiu Hui · Dissection c. 340A Theorem That Doesn't Need a Right AnglePappus of Alexandria · Euclidean 1150BeholdBhāskara II · Dissection c. 1500The Twin HexagonsLeonardo da Vinci · Dissection 1830Perigal's QuarteringHenry Perigal · Dissection 1876The Congressman's TrapezoidJames A. Garfield · Algebraic c. 1881Tip to TailTraditional · Algebraic c. 1891Any Shape Will DoAlbert Einstein (attributed, age 12) · Similar triangles 1988The Leg That GrowsMichael Hardy · Calculus