The Triangle ABC with Vertices $A = \vec { i } + 5 \vec { j }$

True/False

The triangle ABC with vertices $A = \vec { i } + 5 \vec { j }$ , $B = \vec { i } - 3 \vec { j }$ , and $C = - 2 \vec { i } + 2 \vec { j }$ is a right triangle.