Answer
8.5
Work Step by Step
Let $K(-9,8)$ be $(x_1,y_1)$. Let $L(-6,0)$ be $(x_2,y_2)$.
Use the distance formula.
$d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}$
$d=\sqrt{(-6-(-9))^2+(0-8)^2}$
$d=\sqrt{(3)^2+(-8)^2}$
$d=\sqrt{9+64}$
$d=\sqrt{73}$
$d\approx8.5$