Please show step by step

(Section 4.5) 20 points 5. a. Find the area of the triangle in 3-space that has vertices P(1, -1, 2), Q(0, 3, 4) and R(6, 1, 8). b. Given u = (-1, 2, 4), U = (3, 4, -2), w = (-1, 2, 5), compute the scalar triple product u . (3 x w) c. Given u . (U X w) = 3, find the following, i. J. (ux w ) ii. (ux w) . v iii. U. (w x w)