Perimeter · Grade 6

In Grade 6 you learn: perimeter of rectilinear shapes; finding a missing side from the perimeter; shapes with the same area and different perimeters.

The perimeter of a shape is the distance all the way round it: add the lengths of all its sides. For a rectangle, perimeter = 2 × (length + width). Perimeter is a length, so it is measured in cm, m or km.

Key facts

• Rectangle: area = length × width; perimeter = 2 × (length + width).
• Rectilinear shapes: work out any missing sides from the others first.
• Shapes with the same area can have different perimeters.

Worked examples

Other years

• Perimeter · Grade 3
• Perimeter · Grade 4
• Perimeter · Grade 5