Formula to find the surface area of a triangular prism

The table below represents the displacement of a fish from its reef as a function of time: time (hours) x displacement from reef (feet) y 0 4 1 64 2 124 3 184 4 244 part a: what is the y-intercept of the function, and what does this tell you about the fish? (4 points) part b: calculate the average rate of change of the function represented by the table between x = 1 to x = 3 hours, and tell what the average rate represents. (4 points) part c: what would be the domain of the function if the fish continued to swim at this rate until it traveled 724 feet from the reef? (2 points)

Ijust need these 2 questions answered (the second pic is just confirmation i'm not confident in that answer)

Ms. green tells you that a right triangle has a hypotenuse if 13 and a leg of 5. she ask you to find the other leg of the triangle. what is you're answer?