http://www.ck12.org Chapter 7. Vectors
Notice that the father’s force vector (blue) is longer than the force pulling the girl down the hill. This means that
over time they will make progress and ascend the hill. Also note that the father is wasting some of his energy lifting
rather than just pulling. If he could pull at an angle directly opposing the force pulling the girl down the hill, then
he would be using all of his energy efficiently.
- Thexandyaxis are included as reference and note that the gravity vector overlaps with the negativeyaxis. In
order to find each angle, you must use your knowledge of supplementary, complementary and vertical angles and all
the clues from the question. To check, see if all the angles sum to be 360◦.