What is the name of a polygon the has 3 sides and 3 equal angles

Will give brainliest summations with algebraic expressions image shown

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

Reagan lives five miles farther from school than vanessa lives. write an expression to describe how far reagan lives from school