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Class 6

Chapter 6: Perimeter and Area

Perimeter is the total length around a shape. Area is the space inside it. For a rectangle: perimeter = 2(l + w), area = l × w.

Learning outcomes

  • Compute perimeter and area of rectangles & triangles
  • Compare shapes with the same perimeter

Activities

  • Grid-paper shape-design challenge

Worked examples

Read through these first, then try the practice below.

  1. Example 1 — Rectangle area

    Find the area of a rectangle 8 cm long and 5 cm wide.

    Solution: Area = 8 × 5 = 40 cm².

  2. Example 2 — Same perimeter, different area

    Two rectangles each have a perimeter of 16 cm. One is 5×3, the other 4×4. Which has larger area?

    Solution: 5×3 = 15; 4×4 = 16. The square has more area.

Self-do practice

Question 1 of 3 · Score 0/0

What is the perimeter of a rectangle 7 cm by 3 cm?

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