lesson
All the way around
1 · Learn
Perimeter is the total distance around the outside of a flat shape. Count each outside side once.
A rectangle has two pairs of equal opposite sides. If its length is 6 cm and width is 4 cm, its perimeter is 6 + 4 + 6 + 4 = 20 cm.
2 · Worked example
A square with sides of 5 cm has perimeter 4 × 5 = 20 cm. This is a distance, not an area.
3 · Your turn
Find the perimeter of a rectangle 8 cm long and 3 cm wide.
Check your answer
22 cm: 8 + 3 + 8 + 3.
4 · Apply your learning
Draw a small rectangle with a ruler, label every side and trace the boundary as you add.
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Use objects or a drawn model before relying on a rule. Explain each step, check the units and revisit with varied examples. An adult can read the instructions without supplying the answer.
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