1. Maths Unit 10 – Volume and Surface Area
Finding the volume of a shape
Volume of Prism = Area of the cross section x length
The cross-section is the shaded area on each of the prims below.
Sometimes you are given the area of the cross-section but sometimes you need to work this out.
The formulae you should know to be able to so this are below:
Key words and definitions
Volume – a mathematical statement that has two things equal to each other. It consists of two expressions either side of an equals sign.
Surface Area – The area on the outside of a 3D shape.
Prism – a 3D solid which has 2 parallel faces.
Finding the surface area of a 3D shape
Example:
Finding the surface area of the cuboid
To help you visualise the problem:
Draw the net of the shape
Label all the lengths
Use you knowledge of 2D shapes to find the area of each individual face
Add all the faces together to find the total surface area.