It’s multiplication and I need help

I’m on question 7 it says a covered water tank is in the shape of a cylinder the tank has a 28 inch diameter and a height of 66 inches to the nearest square inch what is the surface area of the water tank

In a 45-45-90 right triangle, what is the ratio of the length of one leg to the length of the other leg? а . 1: 2 в. 2: 1 с. 2: 1 d. 1: 1

Non-euclidean geometry was discovered when, in seeking cleaner alternatives to the fifth postulate, it was found that the negation could also be true a. true b.false