<span>A geometric plane is two-dimensional. Standing at one point in the plane and picking two directions to travel which are not opposites of one another, any direction of travel on the plane can be obtained by composing these two directions. Since it is two directions, the plane is two-dimensional.
There is a way of describing this also using algebra. The general equation for a plane is ax + by + c = 0. For example, when a = 2, b = 3, and c = 4, the equation 2x + 3y = 4 is that of a plane. Since there are two variables here, x and y, the plane is two-dimensional.</span>
