Year 10 Trigonometry (Finding Sides) Worksheet — Level 3 — Practice Set 2 — Answers
Answer sheet with worked solutions for the Year 10 trigonometry worksheet.
Year 10 Trigonometry (Finding Sides) Worksheet — Level 3 — Practice Set 2 — Answers
Label the sides (opposite, adjacent, hypotenuse), choose the ratio (SOH CAH TOA), then solve.
1.In a right-angled triangle, the hypotenuse is 21 cm and one angle is 25°. Find the side opposite the 25° angle, to 1 decimal place.
Answer: 8.9 cm
- sin 25° = opposite ÷ hypotenuse
- opposite = 21 × sin 25°
- ≈ 8.9
2.In a right-angled triangle, the hypotenuse is 7 cm and one angle is 66°. Find the side adjacent to the 66° angle, to 1 decimal place.
Answer: 2.8 cm
- cos 66° = adjacent ÷ hypotenuse
- adjacent = 7 × cos 66°
- ≈ 2.8
3.In a right-angled triangle, the hypotenuse is 25 cm and one angle is 50°. Find the side adjacent to the 50° angle, to 1 decimal place.
Answer: 16.1 cm
- cos 50° = adjacent ÷ hypotenuse
- adjacent = 25 × cos 50°
- ≈ 16.1
4.In a right-angled triangle, the hypotenuse is 18 cm and one angle is 24°. Find the side opposite the 24° angle, to 1 decimal place.
Answer: 7.3 cm
- sin 24° = opposite ÷ hypotenuse
- opposite = 18 × sin 24°
- ≈ 7.3
5.In a right-angled triangle, the side adjacent to a 31° angle is 9 m. Find the opposite side, to 1 decimal place.
Answer: 5.4 m
- tan 31° = opposite ÷ adjacent
- opposite = 9 × tan 31°
- ≈ 5.4
6.In a right-angled triangle, the hypotenuse is 27 cm and one angle is 29°. Find the side adjacent to the 29° angle, to 1 decimal place.
Answer: 23.6 cm
- cos 29° = adjacent ÷ hypotenuse
- adjacent = 27 × cos 29°
- ≈ 23.6
7.In a right-angled triangle, the side adjacent to a 54° angle is 19 m. Find the opposite side, to 1 decimal place.
Answer: 26.2 m
- tan 54° = opposite ÷ adjacent
- opposite = 19 × tan 54°
- ≈ 26.2
8.In a right-angled triangle, the side adjacent to a 59° angle is 23 m. Find the opposite side, to 1 decimal place.
Answer: 38.3 m
- tan 59° = opposite ÷ adjacent
- opposite = 23 × tan 59°
- ≈ 38.3
Marking tips
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