In math, the term "distance between two points" refers to the length of a straight line drawn between the two points on an x-y axis. The distance can be determined by finding the change in the y axis and the the x axis and fitting them into the Pythagorean theorem.
The formula for finding the distance between two points in Euclidean geometry, a? + b? = c?, is the same formula that is used to find the length of the hypotenuse of a right triangle. In a three-dimensional plane, the distance between two points must take in the change in the x, y and z coordinates.