# ACT Math: Reviewing Distance Formula

One of the formulas that you’ll want to be familiar with for the ACT Math section is the Distance Formula. It can be used to find the distance, in coordinate units, between two points in the standard (x, y) coordinate plane.

The formula is:

$d = \sqrt{(y_{2}-y_{1})^{2}+(x_{2}-x_{1})^{2}}$

To see how this formula is used, consider the following problem:

What is the distance in the standard (x, y) coordinate plane between the points (8, 3) and (13, 10)?

To answer this question, simply plug the coordinates of the two points into the formula.

$d = \sqrt{(y_{2}-y_{1})^{2}+(x_{2}-x_{1})^{2}}$
$d = \sqrt{(10-3)^{2}+(13-8)^{2}}$
$d = \sqrt{7^{2}+ 5^{2}}$
$d = \sqrt{49 + 25}$
$d = \sqrt{74}$