Perimeter and area · Grade 6
In Grade 6 you learn: area of triangles and parallelograms.
Perimeter is the distance all the way round a shape; area is the amount of flat space it covers, measured in square units. Knowing the area formulas for rectangles, triangles, parallelograms and trapeziums lets you work out compound shapes too.
Key facts
- Rectangle: area = length × width; perimeter = 2 × (length + width).
- Triangle: area = ½ × base × perpendicular height.
- Parallelogram: area = base × perpendicular height.
- 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