Surface area of hemisphere \(= 2πr^2 + πr^2 = 3πr^2\) Example Calculate the volume and surface area of this hemisphere with a diameter of 18 cm. Give answers to the nearest integer.

A cylinder is a 3D shape with a circular cross-section and a curved surface. It has no straight edges. To find the volume or surface area of a cylinder, calculate it in the same way you would a prism.

At the same time each of its 6 faces has an area of 1 m² (1 square meter), and a total surface area of 6 square meters, therefore the surface area to volume ratio (or SA:V for short) is 6/1 = 6 m-1.