We know that coordinates are labeled (x,y) The formula to find slope is (Y2-Y1)/(X2-X1) So (2- (-7))/(-6-(-6) undefined because the denominator is zero. The line looks like a vertical line at x=-6
First you find the lengths of the two vectors, which are both . Then you find the angle given the cos using: cos(∅)= = = 0. Then using ∅=acos(0)= = 90°