The Rhind Mathematical Papyrus is the oldest manuscript written in algebra and trigonometry, dating back to 3,550 years ago. It shows that the Egyptians used first-order equations, geometric series and a second-order algebraic equation, related to the Pythagorean theorem a² + b² = c² It also describes how to obtain an approximation of π accurate to within less than 1% and one of the earliest attempts at squaring the circle.