7.1 #63

I drew a right triangle, facing right. The left vertical side is the lamp. The bottom side is the to length distance from the women to the shadow, and then an additional 4 feet of shadow. You drop a perpendicular line where the ten and four meet. You have two lengths and an angle, so you can find the hypotenuse of the small triangle. When you have the ratio of hypotenuse to base in the small triangle, you can figure it out for the larger, similar triangle.