What is the perimeter of PQR with verticals P(-29) Q(7-3) and R(-2-3) in the coordinate plane?

If you mean vertices of (-2, 9) (7, -3) and (-2, -3) then it is a right angle triangle with an hypotenuse of 15 and sides of 9 and 12 that all add up to 36 which is the perimeter of the triangle.