Find a nonzero vector orthogonal to the plane through the points p, q, and r

Home Work Help
1

(a) Find a nonzero vector orthogonal l to the plane the points P, Q, and R, and
(b) find the area of triangle PQR.
P(1 , 0, 1), Q(- 2,1, 3), R(4, 2, 5)