P6 · Topic
Circles
Circumference = π × d. Area = π × r × r.
Big Idea
Circumference = π × d. Area = π × r × r.
Key points
- 1Diameter = 2 × radius.
- 2Use π = 22/7 or 3.14 as told in the question.
- 3For quarter/half circles, divide the full circle by 4 or 2.
- 4Composite figures: split into parts you know.
Worked example
- 1Area = π × r × r.
- 2Area = 22/7 × 7 × 7 = 154 cm².
Answer: 154 cm²
GYM Teaching Tip
Circle the value of π given so you don't use the wrong one.
See the question behind this example
A circle has radius 7 cm. Using π = 22/7, find its area.