## Geometry: Common Core (15th Edition)

$d=11.7$
Use the distance formula: $d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2+(z_2-z_1)^2}$ $d=\sqrt{(-8-0)^2+(20-12)^2+(12-15)^2}$ $d=\sqrt{(-8)^2+(8)^2+(-3)^2}$ $d=\sqrt{64+64+9}$ $d=\sqrt{137}$ $d\approx11.7$