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Grade 8 · Pythagoras
The Theorem of Pythagoras (Grade 8)
MEMORANDUM
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Class:
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Mark
/ 18
Answer all questions. Show all your working — marks are awarded for method as well as the final answer. Teacher copy: accept any correct equivalent method.
- 1Find the hypotenuse: sides 3 cm and 4 cm.(2)c2 = 9 + 16 = 25 → 5 cm✓✓ (2)
- 2Find the hypotenuse: sides 9 cm and 12 cm.(2)c2 = 81 + 144 = 225 → 15 cm✓✓ (2)
- 3Find the missing side: hypotenuse 10 cm, one side 6 cm.(2)b2 = 100 − 36 = 64 → 8 cm✓✓ (2)
- 4Find the missing side: hypotenuse 25 cm, one side 24 cm.(2)b2 = 625 − 576 = 49 → 7 cm✓✓ (2)
- 5Find the hypotenuse in surd form: sides 1 cm and 2 cm.(2)c2 = 1 + 4 = 5 → 5 cm✓✓ (2)
- 6Find the hypotenuse in surd form: sides 3 cm and 5 cm.(2)c2 = 9 + 25 = 34 → 34 cm✓✓ (2)
- 7Is a triangle with sides 5, 12, 13 right-angled?(2)132 = 169; 25 + 144 = 169 → Yes✓✓ (2)
- 8Is a triangle with sides 6, 7, 10 right-angled?(2)100 vs 36 + 49 = 85 → No✓✓ (2)
- 9A ladder 5 m long rests 3 m from a wall. How high up the wall does it reach?(2)h2 = 25 − 9 = 16 → 4 m✓✓ (2)
TOTAL: 18 marks