Area · Grade 7

In Grade 7 you learn: area of triangles and parallelograms; area of trapeziums.

Area is the amount of flat space a shape covers, measured in square units such as cm² and m². Count the squares, or use the formula for the shape; a compound shape splits into simpler shapes.

Key facts

  • Rectangle: area = length × width; perimeter = 2 × (length + width).
  • Triangle: area = ½ × base × perpendicular height.
  • Parallelogram: area = base × perpendicular height.
  • Trapezium: area = ½ × (a + b) × h, where a and b are the parallel sides.
  • Compound shapes: split into rectangles (or subtract a missing piece). Use the same units throughout.

Worked examples

Example 1

Find the area of this L-shape. All corners are right angles; lengths are in cm.

Answer: 55 cm²

Example 2

A triangle has a base of 10 cm and a perpendicular height of 7 cm. Find its area.

Answer: 35 cm²

Example 3

A lawn 12 m by 8 m has a path 1 m wide all round it. Find the area of the path.

Answer: 44 m²

Example 4

A trapezium has parallel sides of 6 cm and 10 cm and a height of 5 cm. Find its area.

Answer: 40 cm²

Other years