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Grade 10 · Trigonometry
Trigonometry: Solving Triangles & Angles of Elevation
MEMORANDUM
Name:
Class:
Date:
Mark
/ 16
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 x: opposite a 40° angle, hypotenuse 15 cm.(2)15 sin 40° = 9,64 cm✓✓ (2)
- 2Find x: adjacent to a 55° angle, hypotenuse 20 cm.(2)20 cos 55° = 11,47 cm✓✓ (2)
- 3Find x: opposite a 30° angle, adjacent 12 cm.(2)12 tan 30° = 6,93 cm✓✓ (2)
- 4Find θ: opposite 7, adjacent 10.(2)tan⁻¹(0,7) = 35,0°✓✓ (2)
- 5Find θ: opposite 5, hypotenuse 13.(2)sin⁻¹(5/13) = 22,6°✓✓ (2)
- 6Find θ: adjacent 8, hypotenuse 17.(2)cos⁻¹(8/17) = 61,9°✓✓ (2)
- 7From 120 m away the elevation to a tower top is 34°. Find its height.(2)120 tan 34° = 80,94 m✓✓ (2)
- 8What is the difference between an angle of elevation and one of depression?(2)Elevation is measured up from the horizontal; depression is measured down.✓✓ (2)
TOTAL: 16 marks