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Grade 6 · Math · Unit 12 of 18

Perimeter & Area

Triangles, parallelograms, trapezoids

What your child practises

Finding the perimeter of L-shapes and other polygons, and the area of triangles (b × h ÷ 2), parallelograms (b × h) and trapezoids ((a + b) × h ÷ 2), including working backwards to a missing measurement.

Prince Edward Island Curriculum curriculum outcome: SS3 · perimeter and area of polygons using formulas

How we explain it

Children can open this short lesson before they practise.

  1. Perimeter is the distance around. Add every side.
  2. Triangle area = base × height ÷ 2.
  3. Parallelogram area = base × height. Trapezoid area = (a + b) × height ÷ 2.

Example: A triangle has a base of 8 cm and a height of 5 cm. What is its area? 8 × 5 = 40. 40 ÷ 2 = 20. Answer: 20 cm²

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    Join the points in order, A to F, then back to A. Each grid square is 1 m long. What is the perimeter of the shape?

    001122334455667788991010ABCDEF

    answer boxm

  2. Question 2

    A trapezoid has parallel sides of 3 cm and 7 cm, and a height of 2 cm. What is its area?

    answer boxcm²

  3. Question 3

    A parallelogram has an area of 36 cm² and a base of 9 cm. What is its height?

    answer boxcm

  4. Question 4

    A triangular sail has a base of 2 m and a height of 5 m. How much fabric covers the sail?

    • 5 m²
    • 10 m²
    • 7 m²
    • 14 m²

  5. Question 5

    A garden shaped like a pentagon has a perimeter of 55 m. 4 of its sides are 12 m, 12 m, 10 m and 14 m. How long is the last side?

    answer boxm

  6. Question 6

    A parallelogram has a base of 13 m, slanted sides of 12 m, and a height of 10 m. What is its area?

    answer boxm²

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