Year 9 Area and Perimeter Worksheet — Level 2 — Practice Set 4 — Answers
Answer sheet with worked solutions for the Year 9 area & perimeter worksheet.
Success TutoringWorksheetsAnswer sheetYear 9 · Mathematics · Area & PerimeterYear 9 Area and Perimeter Worksheet — Level 2 — Practice Set 4 — Answers
Write the formula, substitute, then calculate. Include units.
1.A triangle has a base of 19 mm and a perpendicular height of 13 mm. Find its area.
Answer: 123.5 mm2
- A = ½ × base × height = ½ × 19 × 13
- = 123.5 mm2
2.A rectangle is 13 m long and 14 m wide. Find its area.
Answer: 182 m2
- A = length × width = 13 × 14
- = 182 m2
3.A rectangle is 18 cm long and 8 cm wide. Find its area.
Answer: 144 cm2
- A = length × width = 18 × 8
- = 144 cm2
4.A rectangle is 21 m long and 2 m wide. Find its perimeter.
Answer: 46 m
- P = 2 × (21 + 2)
- = 2 × 23 = 46 m
5.A triangle has a base of 20 cm and a perpendicular height of 12 cm. Find its area.
Answer: 120 cm2
- A = ½ × base × height = ½ × 20 × 12
- = 120 cm2
6.A rectangle is 8 mm long and 20 mm wide. Find its area.
Answer: 160 mm2
- A = length × width = 8 × 20
- = 160 mm2
7.A rectangle is 23 m long and 2 m wide. Find its perimeter.
Answer: 50 m
- P = 2 × (23 + 2)
- = 2 × 25 = 50 m
8.A triangle has a base of 4 m and a perpendicular height of 14 m. Find its area.
Answer: 28 m2
- A = ½ × base × height = ½ × 4 × 14
- = 28 m2
9.A rectangle is 20 m long and 15 m wide. Find its area.
Answer: 300 m2
- A = length × width = 20 × 15
- = 300 m2
10.A triangle has a base of 20 mm and a perpendicular height of 10 mm. Find its area.
Answer: 100 mm2
- A = ½ × base × height = ½ × 20 × 10
- = 100 mm2
Marking tips
- Give credit for correct method even when the final answer slips — the working shows where the thinking went right.
- For open-ended tasks, use the success criteria as a checklist rather than looking for one "right" answer.
- Celebrate what went well first, then pick one thing to work on next.