I need 3, 4, 5 pretty pease

Which best explains why this triangle is or is not a right triangle?

Mr.walker is looking at the fundraiser totals for the last five years , how does the mean of the totals compare to the median?

Margie is practicing for an upcoming tennis tournament. her first serve is good 20 out of 30 times on average. margie wants to know the estimated probability that her first serve will be good at least four of the next six times she serves. how could she design a simulation for this scenario?