Answer
$3\sqrt{10}$
Work Step by Step
We find the distance between the first and fourth points, $(0,-6)$ and $(3,3)$ by using the distance formula:
$d=\sqrt{(x_1-x_2)^2+(y_1-y_2)^2)}$
$d=\sqrt{(3-0)^{2}+(3-(-6))^{2}}$
$=\sqrt{3^{2}+9^{2}}$
$=\sqrt{9+81}$
$=\sqrt{90}$
$=\sqrt{9*10}$
$=3\sqrt{10}$