Through: (1, -4), perp. to y = 1/4-x - 4

Part A:

0 = the surface of the swimming pool

Part B:

Since the height of the slide is measured at +10 feet, then this means

that the top of the slide is 10 feet above the surface of the water (0) in the swimming pool.

Part C:

Since 3 feet of the pole was put in the water, then Kayla should mark the of the bottom of the pole as -3 feet.