How do you find the surface area of the cylinder radius=10 height= 7.5

The figures below are made out of circles, semicircles, quarter circles, and a square. find the area and the perimeter of each figure and give your answers as a completely simplified exact value in terms of π (no approximations).

Look at this pattern ; 1,4,9, number 10000 belongs in this pattern . what’s the place of this number?

The difference of three and the reciprocal of a number is equal to the quotient of 20 and the number. find the number.