In a Cartesian coordinate system in the plane, the distance d between two points \((x_1, y_1\)) and (\(x_2, y_2\)) is: d = \(\sqrt{(x_2-x_1)^{2}+(y_2-y_1)^{2}}\).
Example
The distance d between the points P(1, 2) and Q(4, 6) is: d = \(\sqrt{(4-1)^{2}+(6-2)^{2}}\) = \(\sqrt{25}\) = 5.