The Distance Formula in 3 Dimensions

You know that the distance $AB$ between two points in a plane with Cartesian coordinates $A\left(x_1,y_1\right)$ and $B\left(x_2,y_2\right)$ is given by the following formula:

$AB=\sqrt{{\left(x_2-x_1\right)}^2+{\left(y_2-y_1\right)}^2}$

In three-dimensional Cartesian space, points have three coordinates each. To find the distance between $A\left(x_1,y_1,z_1\right)$ and $B\left(x_2,y_2,z_2\right)$ , use the formula:

$AB=\sqrt{{\left(x_2-x_1\right)}^2+{\left(y_2-y_1\right)}^2+{\left(z_2-z_1\right)}^2}$