Circles & Compound Shapes
π ≈ 3.14 links a circle's diameter to its circumference.
Parts of circlesCircumferenceArea of a circleCompound shapesCircle problems
📖 Learn
Parts
Radius = centre to edge. Diameter = 2 × radius.
Circumference
C = π × d.
Area
A = π × r². Square the radius first!
Worked example
Area of a circle, radius 3 cm (use π = 3.14)
- 1r² = 9
- 23.14 × 9
- 3= 28.26 cm² ✅
⭐ Practise
π
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