Year 9 Pythagoras' Theorem Worksheet — Level 1 — Answers
Answer sheet with worked solutions for the Year 9 pythagoras' theorem worksheet.
Year 9 · Mathematics · Pythagoras' Theorem
Year 9 Pythagoras' Theorem Worksheet — Level 1 — Answers
Success Tutoring
Use c² = a² + b², where c is the hypotenuse. Show your working.
1.A right-angled triangle has shorter sides of 8 cm and 15 cm. Find the length of the hypotenuse.
Answer: 17 cm
- c2 = 82 + 152
- c2 = 64 + 225 = 289
- c = √289 = 17
2.A right-angled triangle has shorter sides of 7 cm and 24 cm. Find the length of the hypotenuse.
Answer: 25 cm
- c2 = 72 + 242
- c2 = 49 + 576 = 625
- c = √625 = 25
3.A right-angled triangle has shorter sides of 12 cm and 16 cm. Find the length of the hypotenuse.
Answer: 20 cm
- c2 = 122 + 162
- c2 = 144 + 256 = 400
- c = √400 = 20
4.A right-angled triangle has shorter sides of 15 cm and 20 cm. Find the length of the hypotenuse.
Answer: 25 cm
- c2 = 152 + 202
- c2 = 225 + 400 = 625
- c = √625 = 25
5.A right-angled triangle has shorter sides of 6 cm and 8 cm. Find the length of the hypotenuse.
Answer: 10 cm
- c2 = 62 + 82
- c2 = 36 + 64 = 100
- c = √100 = 10
6.A right-angled triangle has shorter sides of 9 cm and 12 cm. Find the length of the hypotenuse.
Answer: 15 cm
- c2 = 92 + 122
- c2 = 81 + 144 = 225
- c = √225 = 15
7.A right-angled triangle has shorter sides of 3 cm and 4 cm. Find the length of the hypotenuse.
Answer: 5 cm
- c2 = 32 + 42
- c2 = 9 + 16 = 25
- c = √25 = 5
8.A right-angled triangle has shorter sides of 9 cm and 40 cm. Find the length of the hypotenuse.
Answer: 41 cm
- c2 = 92 + 402
- c2 = 81 + 1600 = 1681
- c = √1681 = 41
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.
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