Reference / Curriculum / 3B / Chapter 13

3B · Chapter 13 · consolidation

Practice B

Original cumulative chapter practice to consolidate taught ideas.

Original cumulative chapter practice to consolidate taught ideas. Solutions are available as revealable feedback and in a separate complete answer key. No answer submissions or accounts are required.

Assessment · 18 questions

Questions

Show your thinking; use diagrams when they help. Do not open solutions during your first attempt.

  1. A1

    A rectangular garden covers 6 rows of 5 equal unit squares. Find its area.

    Reveal explanation

    Answer: 30 square units

    There are 6 rows of 5 equal square units: 5 × 6 = 30 square units.

    Each visible square is 1 square unit.
    Square-unit grid; count only visible squares without gaps or overlap.
  2. A2

    A tiled mat is 9 square units across and 3 square units down. How many unit squares cover it?

    Reveal explanation

    Answer: 27 square units

    There are 3 rows of 9 equal square units: 9 × 3 = 27 square units.

    Each visible square is 1 square unit.
    Square-unit grid; count only visible squares without gaps or overlap.
  3. A3

    A rectangle is 5 unit squares across and 2 unit squares down. What is its area?

    Reveal explanation

    Answer: 10 square units

    There are 2 rows of 5 equal square units: 5 × 2 = 10 square units.

    Each visible square is 1 square unit.
    Square-unit grid; count only visible squares without gaps or overlap.
  4. A4

    A 4-by-4 rectangle has a 2-by-3 corner removed. Find the remaining area in square units.

    Reveal explanation

    Answer: 10 square units

    Whole rectangle: 4 × 4 = 16. Missing corner: 2 × 3 = 6. Remaining: 16 − 6 = 10.

    Each visible square is 1 square unit.
    Square-unit grid; count only visible squares without gaps or overlap.
  5. A5

    A rectangular fence is 4 cm long and 5 cm wide. What length of edging goes all the way around?

    Reveal explanation

    Answer: 18 cm

    Walk along every outer edge once: 4 + 5 + 4 + 5 = 18 cm.

    Each visible square is 1 square unit.
    Square-unit grid; count only visible squares without gaps or overlap.
  6. A6

    A rectangle measures 9 cm by 6 cm. What is its perimeter?

    Reveal explanation

    Answer: 30 cm

    Walk along every outer edge once: 9 + 6 + 9 + 6 = 30 cm.

    Each visible square is 1 square unit.
    Square-unit grid; count only visible squares without gaps or overlap.
  7. A7

    A 4-by-3 rectangle has what area and what perimeter? Include units.

    Reveal explanation

    Answer: 12 square units; 14 units

    Area counts square units: 4 × 3 = 12. Perimeter counts the boundary: 2(4+3) = 14. They have different units.

    Each visible square is 1 square unit.
    Square-unit grid; count only visible squares without gaps or overlap.
  8. A8

    A rectangular garden covers 4 rows of 7 equal unit squares. Find its area.

    Reveal explanation

    Answer: 28 square units

    There are 4 rows of 7 equal square units: 7 × 4 = 28 square units.

    Each visible square is 1 square unit.
    Square-unit grid; count only visible squares without gaps or overlap.
  9. A9

    A tiled mat is 7 square units across and 5 square units down. How many unit squares cover it?

    Reveal explanation

    Answer: 35 square units

    There are 5 rows of 7 equal square units: 7 × 5 = 35 square units.

    Each visible square is 1 square unit.
    Square-unit grid; count only visible squares without gaps or overlap.
  10. A10

    A rectangle is 4 unit squares across and 2 unit squares down. What is its area?

    Reveal explanation

    Answer: 8 square units

    There are 2 rows of 4 equal square units: 4 × 2 = 8 square units.

    Each visible square is 1 square unit.
    Square-unit grid; count only visible squares without gaps or overlap.
  11. A11

    A 9-by-3 rectangle has a 2-by-2 corner removed. Find the remaining area in square units.

    Reveal explanation

    Answer: 23 square units

    Whole rectangle: 9 × 3 = 27. Missing corner: 2 × 2 = 4. Remaining: 27 − 4 = 23.

    Each visible square is 1 square unit.
    Square-unit grid; count only visible squares without gaps or overlap.
  12. A12

    A rectangular fence is 4 cm long and 6 cm wide. What length of edging goes all the way around?

    Reveal explanation

    Answer: 20 cm

    Walk along every outer edge once: 4 + 6 + 4 + 6 = 20 cm.

    Each visible square is 1 square unit.
    Square-unit grid; count only visible squares without gaps or overlap.
  13. A13

    A rectangle measures 6 cm by 3 cm. What is its perimeter?

    Reveal explanation

    Answer: 18 cm

    Walk along every outer edge once: 6 + 3 + 6 + 3 = 18 cm.

    Each visible square is 1 square unit.
    Square-unit grid; count only visible squares without gaps or overlap.
  14. A14

    A 5-by-5 rectangle has what area and what perimeter? Include units.

    Reveal explanation

    Answer: 25 square units; 20 units

    Area counts square units: 5 × 5 = 25. Perimeter counts the boundary: 2(5+5) = 20. They have different units.

    Each visible square is 1 square unit.
    Square-unit grid; count only visible squares without gaps or overlap.
  15. A15

    A rectangular garden covers 3 rows of 9 equal unit squares. Find its area.

    Reveal explanation

    Answer: 27 square units

    There are 3 rows of 9 equal square units: 9 × 3 = 27 square units.

    Each visible square is 1 square unit.
    Square-unit grid; count only visible squares without gaps or overlap.
  16. A16

    A tiled mat is 3 square units across and 2 square units down. How many unit squares cover it?

    Reveal explanation

    Answer: 6 square units

    There are 2 rows of 3 equal square units: 3 × 2 = 6 square units.

    Each visible square is 1 square unit.
    Square-unit grid; count only visible squares without gaps or overlap.
  17. A17

    A student says a rectangle with area 36 square units must have perimeter 36 units. Explain why this is not generally true using a 6-by-6 example.

    Reveal explanation

    Answer: Perimeter 24 units

    The area is 6 × 6 = 36 square units, but its perimeter is 2 × (6+6) = 24 units. Area and perimeter measure different things.

  18. A18

    A 5-by-6 rectangle and a 1-by-30 rectangle have the same area. Must they have the same perimeter?

    Reveal explanation

    Answer: No

    Both areas are equal, but different side dimensions usually give different boundary lengths.

Continue →Complete answer key