Mensuration: Cubes, Cuboids, Cones and Cylinders | Form 2 Mathematics

Mensuration: Cubes, Cuboids, Cones and Cylinders

The volume of a solid measures the space it occupies, while surface area measures the outside covering.

Formulas

• Cube: V = a³, TSA = 6a².
• Cuboid: V = lwh, TSA = 2(lw + lh + wh).
• Cylinder: V = πr²h.
• Cone: V = 1/3πr²h.

Worked examples

1. A cuboid 4 cm × 3 cm × 5 cm has volume 60 cm³.
2. A cone with r = 3 cm and h = 7 cm has V = 1/3π × 9 × 7 = 21π cm³.
3. A cylinder with diameter 10 cm and height 12 cm has r = 5 cm and V = 300π cm³.

Practice

1. Find the TSA of a cube of side 6 cm.
2. Find the volume of a cylinder with radius 4 cm and height 10 cm.
3. Find the volume of a cuboid 2.5 m by 1.2 m by 0.8 m.