Mathematical formulae; and their explanation : - ( Plan Analytical Geometry ) - 8.

Two-dimensional (2D) geometry, or plane geometry, combines geometry and algebra that uses graphs to solve problems. It deals with the x and y coordinate plane, or Cartesian plane, which has two axes: a horizontal x-axis and a vertical y-axis. Points in 2D space are assigned coordinates that uniquely identify them, and are measured concerning the coordinate axes.