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Primary 3 Maths: Perimeter and Length — Practice Paper 4 (10 Questions)
Primary 3 Maths: Perimeter and Length — Practice Paper 4 (10 Questions)
Paper 4 turns the perimeter round and works backwards: from a perimeter to a width, from a perimeter to a side, and from a shape cut in two to the two new perimeters. The last item redoes the square that was only doubled.
Quick answer 10 questions, about 20 minutes. Items 01 to 03 cover a rectangle, a square and metres to centimetres; items 04 to 06 cover a perimeter worked backwards to a width, an equilateral triangle from its perimeter and an isosceles triangle; items 07 to 09 cover a rectangle cut in two, a fence on three sides against a wall and a wire rebent into a rectangle; item 10 redoes the square doubled instead of multiplied by four.
01 Paper details (check answers afterwards)
| Item | Detail |
|---|---|
| Questions | 10 questions |
| Suggested time | 20 minutes |
| Difficulty mix | Foundation 3 · Intermediate 3 · Challenge 3 · Error redo 1 |
| Chapter | Chapter: Primary 3 Maths: Perimeter and Length — Tutor Lesson Plan |
| Level | Primary 3 |
02 Questions (10 items)
- FoundationA rectangle is 18 cm long and 9 cm wide. What is its perimeter?
- FoundationA square has sides of 12 cm. What is its perimeter?
- FoundationConvert: (a) 3 m 5 cm into cm; (b) 705 cm into m and cm.
- IntermediateA rectangle has a perimeter of 60 cm and a length of 21 cm. What is its width?
- IntermediateAn equilateral triangle has a perimeter of 45 cm. How long is each side?
- IntermediateAn isosceles triangle has two equal sides of 12 cm and a base of 9 cm. What is its perimeter?
- ChallengeA rectangle 25 cm by 16 cm is cut along the midline parallel to its length into two equal rectangles. What is the perimeter of each, and how much more do the two perimeters add up to than the original?
- ChallengeA rectangular flower bed is built against a wall and only three sides are fenced. The fence is 24 m long and the side against the wall is 10 m. What is the width?
- ChallengeA piece of wire makes a square with a perimeter of 36 cm, then is rebent into a rectangle 14 cm long. What is its width?
- Error redoFor a square of side 8 cm a student answers a perimeter of 16 cm. What went wrong, and what is the right answer?
03 Answers and one-line notes
| # | Answer | One-line note |
|---|---|---|
| 1 | 54 cm | (18 + 9) × 2 = 54, and 18 + 9 + 18 + 9 = 54 confirms it: the four sides add up to the same total. |
| 2 | 48 cm | A square has four equal sides, so 12 × 4 = 48 cm; adding 12 four times gives the same 48. |
| 3 | (a) 305 cm; (b) 7 m 5 cm | 1 m = 100 cm, so 3 m 5 cm = 300 + 5 = 305 cm. In 705 cm there are seven lots of 100 cm with 5 cm left over. |
| 4 | 9 cm | Half the perimeter, 60 ÷ 2 = 30, is one length plus one width, so 30 − 21 = 9. The check is 2 × (21 + 9) = 60. |
| 5 | 15 cm | An equilateral triangle has three equal sides, so divide the perimeter by 3: 45 ÷ 3 = 15 cm, and 15 × 3 = 45 checks it. |
| 6 | 33 cm | The two equal sides are added with the base: 12 + 12 + 9 = 33 cm. Only two sides are equal, so the base is not multiplied by 3. |
| 7 | Each is 66 cm; together they are 50 cm more | Each piece is 25 cm by 8 cm, so its perimeter is 2 × (25 + 8) = 66 cm. The two together give 132 against the original 82, which is 50 cm more: exactly the two cut edges. |
| 8 | 7 m | The wall side needs no fence, so 24 − 10 = 14 covers the two widths and 14 ÷ 2 = 7 m. The check is 10 + 7 + 7 = 24. |
| 9 | 4 cm | The wire keeps its length, so the perimeter stays 36 cm. Half of it, 18, is one length plus one width, and 18 − 14 = 4; the check is 2 × (14 + 4) = 36. |
| 10 | Only two sides were counted; the perimeter is 32 cm | 16 is 8 × 2, which counts only two sides. A square has four sides, so multiply by 4: 8 × 4 = 32 cm. |
04 What to do after marking
- After marking, redo only the wrong items and write down which step went wrong (formula, unit, or misread number).
- Repeat the same item two days later; move to the next paper only when both attempts are correct.
- Parents only need the answer and note columns; there is no need to explain every item.
Questions and answers are written originally by the TutorZone team and are not taken from any school, publisher or examination authority paper. Every value is checked by computer.
