Summary
Understanding how to calculate areas and perimeters of two-dimensional shapes is essential. You will also learn to handle shapes that can be divided into simpler polygons.
- Perimeter — the length of the outline of a shape. Example: The perimeter of a rectangle is found by adding the lengths of all four sides.
- Area — the measurement of the surface of a shape. Example: The area of a rectangle is calculated by multiplying its length by its width.
Exam Tips
Key Definitions to Remember
- Perimeter is the distance around the outside of a two-dimensional shape.
- Area is the space contained within the sides of a two-dimensional shape.
Common Confusions
- Confusing perimeter with area.
- Forgetting to use squared units for area.
Typical Exam Questions
- How do you find the perimeter of a rectangle? Add the lengths of all four sides.
- How do you calculate the area of a rectangle? Multiply the length by the width.
- What is the area of a triangle with a base of 33 cm and height of 16 cm? Area = 0.5 x base x height = 264 cm²
What Examiners Usually Test
- Ability to calculate areas and perimeters of basic shapes.
- Understanding of units and conversion between them.
- Application of area and perimeter calculations to composite shapes.