Area of Parallelograms — Solutions

1. Calculate the Area

   1. 60 cm² ▶ View Solution
   2. 40 m² ▶ View Solution
   3. 60 cm² ▶ View Solution
   4. 28 m² ▶ View Solution
   5. 81 cm² ▶ View Solution

2. Find the Missing Dimension

   1. 6 cm ▶ View Solution
   2. 15 m ▶ View Solution
   3. 5 cm ▶ View Solution
   4. 12 mm ▶ View Solution
   5. 7 m ▶ View Solution

3. Units and Conversion

   1. 15 cm² ▶ View Solution
   2. 1.6 m² ▶ View Solution
   3. 5 400 cm² ▶ View Solution
   4. 1 500 mm² ▶ View Solution

4. Compare and Reason

   1. 60 cm² vs 80 cm² — second is greater by 20 cm² ▶ View Solution
   2. 7 cm ▶ View Solution
   3. Area depends on perpendicular height, not slant side; with the same base the taller parallelogram has greater area ▶ View Solution
   4. 63 cm² — rearranging does not change area ▶ View Solution

5. Problem Solving

   1. 21 m² ▶ View Solution
   2. 0.96 m² ▶ View Solution
   3. 2.5 litres ▶ View Solution
   4. $1 200 ▶ View Solution
   5. b ≈ 8.64 cm, h ≈ 6.48 cm ▶ View Solution

6. More Calculate the Area

   1. 77 cm² ▶ View Solution
   2. 84 m² ▶ View Solution
   3. 20 cm² ▶ View Solution
   4. 99 mm² ▶ View Solution
   5. 36 m² ▶ View Solution

7. Spot the Error

   1. Error: used slant side (6 cm) instead of perpendicular height (4 cm); correct: 40 cm² ▶ View Solution
   2. Error: used ½bh (triangle formula); correct: 40 m² ▶ View Solution
   3. Error: added base and height instead of multiplying; correct: 60 mm² ▶ View Solution
   4. Error: a rectangle IS a parallelogram so A = bh applies; correct: 54 cm² ▶ View Solution

8. Area and Perimeter Together

   1. Perimeter = 40 cm; Area = 72 cm² — different units, cannot be equal ▶ View Solution
   2. First: 60 cm²; second: 80 cm² — second is greater despite same perimeter ▶ View Solution
   3. P = 2(b + s) ▶ View Solution
   4. Area = 45 cm²; Perimeter = 32 cm ▶ View Solution

9. Parallelograms in Composite Figures

   1. 208 cm² ▶ View Solution
   2. 400 tiles ▶ View Solution
   3. 60 m² ▶ View Solution
   4. b ≈ 9.8 cm, h ≈ 4.9 cm ▶ View Solution
   5. 70 cm² ▶ View Solution

10. Extended Investigation

    1. Rectangle height = 8 cm (both areas = 80 cm²) ▶ View Solution
    2. h = 7 m; Perimeter = 28 m ▶ View Solution
    3. 0.72 m² ▶ View Solution
    4. A rectangle is a parallelogram with all 90° angles; perpendicular height equals the width, so A = b × h is the same as length × width ▶ View Solution