That is not the way to do it.
find the angles of the triangle formed by the points P(2,-2,5), Q(2,1,7) and R(7,6,-10)
do i use the dot product for this? which pairs would i use? does anyone know how to do this?
I got the following angles, are these right?
between P & Q = 28.8 degrees
" Q & R = 120 degrees
" P & R = 127.9 degrees