Two forces, F1 and F2, are represented by vectors with initial points that are at the origin. The first force has a magnitude of 20 lb and the terminal point of the vector is point P(1, 1, 0). The second force has a magnitude of 80 lb and the terminal point of its vector is point Q(0, 1, 1). Let F be the resultant force of forces F1 and F2. (a) Find the magnitude (in pounds) of F. (Round the answer to one decimal place.)