D. 17
1) To find the length of that side, let's use the distance formula derived from the Pythagorean Theorem.
[tex]\begin{gathered} d=\sqrt[]{(x_2-x_1)^2+(y_2-y_1)^2} \\ d=\sqrt[]{(-7-(-7))^2+(-6-11)^2} \\ d=\text{ 17} \end{gathered}[/tex]2) So the distance between those two points, i.e. the side of that triangle measures 17 units.
