To work out the surface area of a 3D shape is the same as thinking about how much paint you would need in order to paint the whole outside of the shape.
1. Work out how many different shapes are needed to make up the shape.
2. Then solve the area of each shape individually.
3. Finally add them all up to find out the whole surface area.
To work out the volume of a cone:
1. Work out the area of the base of the cone. To do this the formula is π r3
2. Then times the area by the height of the cone (make sure it is the height in the middle of the cone, not the slanted angle on one of the sides).
3. Finally divide your total by 3 to find your final answer.