Perimeter, Area & Volume
Find the perimeter and area of rectangles, triangles and compound shapes, and the volume of cuboids.
Overview
Perimeter is the distance around a shape, area is the space inside it, and volume is the space inside a solid. In Year 7 students find the perimeter and area of rectangles, triangles and compound shapes, and the volume of cuboids. Keeping the units correct — for example cm for length, cm² for area and cm³ for volume — is essential.
What You Will Learn
- Find the perimeter of rectangles, triangles and compound shapes
- Find the area of a rectangle using length × width
- Find the area of a triangle using ½ × base × height
- Find the area of a compound shape by splitting it into rectangles and triangles
- Find the volume of a cuboid using length × width × height
Key Vocabulary
Common Mistakes to Avoid
- Confusing perimeter with area
- Forgetting the ½ in the area of a triangle
- Using the slant side instead of the perpendicular height of a triangle
- Giving area in cm instead of cm², or muddling units between length, area and volume
What Comes Next
Year 8 extends this to the area of parallelograms and trapezia and the volume of prisms, and Year 9 reaches circles and harder compound solids. This becomes the IGCSE Mensuration topic.
Frequently Asked Questions
What is the difference between area and perimeter?
Perimeter is the total distance around the outside of a shape, measured in length units. Area is the amount of surface inside the shape, measured in square units.
Why is the area of a triangle half of base times height?
A triangle is exactly half of a rectangle with the same base and height, so its area is half of base × height.
Study This Topic
Topic Details
- Stage
- Year 7
- Strand
- Geometry and Measure
- Framework ref
- 7Gg
- Difficulty
- Medium
Build strong foundations in Perimeter, Area & Volume
A free trial class with Teacher Rig helps your Year 7 child master Perimeter, Area & Volume now — so IGCSE Maths feels familiar, not frightening, later.
Heading toward IGCSE? See how Perimeter, Area & Volume develops in IGCSE Mensuration (Cambridge 0580) →