cylinder
<h2>Step-by-step explanation:</h2>Archimedes was a brilliant mathematician. This man rose the formula of the volume of a sphere by comparing this shape to a cylinder. The volume of a sphere is hard to calculate by comparing this object to a cube. So Archimedes imagined cutting a sphere into two halves, called hemispheres. So an hemisphere gave him a flat surface, which is easier to work with. Therefore, if he'd find the volume of a hemisphere, then he'd multiply the result by 2 and would get the volume of a sphere. Then he imagined a hemisphere within a cylinder as the one shown below. Also, he imagined a cone within the same cylinder. <em>What did he find? </em>He found that the volume of the hemisphere should be equal to the volume of the cylinder minus the volume of the cone:
Then the volume of a sphere is twice this volume:
