Volume
- Volume is the amount of space inside a 3D shape, measured in cubic units such as cm³ and m³.
- Cuboid: length × width × height. A cuboid 5 cm by 4 cm by 3 cm has a volume of 60 cm³. Cube: side × side × side.
- Prism: area of the cross-section × length. A triangular prism with a triangle of base 4 cm and height 3 cm, and a length of 10 cm, has a volume of 6 × 10 = 60 cm³.
- Cylinder: π × radius² × height.
Surface area
- The surface area is the total area of all the faces. Sketch the net to help.
- A cuboid has three pairs of faces: surface area = 2 × (lw + lh + wh). A cube with sides of 2 cm has a surface area of 6 × 4 = 24 cm².
Capacity
- Capacity is how much a container holds. 1 cm³ = 1 ml, and 1000 cm³ = 1 litre.
- 1 m³ = 1 000 000 cm³ = 1000 litres.
Key terms
- Volume
- The amount of space inside a 3D shape.
- Cubic centimetre
- A unit of volume: a cube with sides of 1 cm (cm³).
- Cuboid
- A 3D shape with six rectangular faces.
- Prism
- A 3D shape with the same cross-section all along its length.
- Cross-section
- The shape you see when you cut straight through a prism.
- Surface area
- The total area of all the faces of a 3D shape.
- Capacity
- How much a container can hold.
- Litre
- A unit of capacity equal to 1000 cm³.