If dealing with 3D shapes you might be asked to find the surface area of a shape. One way may be to look at its net.

**Nets**

A net is just a 3D shape folded flat. E.g. here is the net of a square.In a questions you can find the surface area just by adding up all the areas of the shapes that make the net.

**Surface Area Of A Sphere**

Surface area of a sphere = 4π*r*2

**Surface Area Of A Cone**

Surface area of a cone = π*rl* + π*r*2

Note: l is the slanted height.**Surface Area Of A Cylinder**

Surface area of a cylinder = 2*πrh *+ 2π*r*2