Area
Perimeter is the fence around; area is the grass inside.
PerimeterSquares & rectanglesCompound shapesTrianglesParallelogramsTrapezia
📖 Learn
Rectangle
Area = length × width. Perimeter = add all sides.
Triangle & parallelogram
Triangle = ½ × base × height. Parallelogram = base × height (perpendicular!).
Trapezium
Area = ½ × (a + b) × h, where a and b are the parallel sides.
Worked example
Triangle with base 10 cm, height 6 cm
- 1½ × base × height
- 2½ × 10 × 6
- 3= 30 cm² ✅
⭐ Practise
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