How did Rene Descartes discover the cartesian plane?

René Descartes discovered the Cartesian plane through his work in mathematics and philosophy, particularly by combining algebra and geometry. He developed a coordinate system that allows geometric shapes to be expressed in algebraic equations, which he described in his 1637 work "La Géométrie." By defining a plane using two perpendicular axes (x and y), he enabled the representation of points as ordered pairs, thus laying the foundation for analytic geometry. This innovative approach allowed for the visualization of mathematical concepts and the solving of geometric problems using algebra.