Distance formula - Part I

This post is going to explain the distance formula... what it is, and where it comes from. When you see how to derive it, you won't need to worry about memorizing the formula anymore. And it's much easier than you think, despite looking kind of scary.

The distance formula can best be explained with a right angle triangle.

Assume that you want to find the distance between 2 points... if you extend a horizontal line across from one point, and a vertical line through the other, these two lines will intersect at a right angle. You can then imagine the hypotenuse of this right angle triangle to be the distance between the 2 points in question.

From this, you can see that the distance between the two points is simply the length of the hypotenuse. Move ahead to the next page, where I will describe the formula that we need!

formula of distance