Casey was at the surface of a swimming pool and recorded the following two measurements, in feet, on a number line: −8, which represents the depth of water in the swimming pool +7, which represents the height of the slide at the pool part a: what does 0 represent in this situation? (3 points) part b: describe the height of the slide in relation to 0 in the situation. (3 points) part c: casey held a pole in the swimming pool. the bottom of the pole was at a depth of 2 feet. how should casey mark the level of the bottom of the pole on the number line? explain how you determined this. (4 points)