Year 10 Trigonometry (Finding Sides) Worksheet — Level 3 — Practice Set 3 — Answers
Answer sheet with worked solutions for the Year 10 trigonometry worksheet.
Year 10 Trigonometry (Finding Sides) Worksheet — Level 3 — Practice Set 3 — Answers
Label the sides (opposite, adjacent, hypotenuse), choose the ratio (SOH CAH TOA), then solve.
1.In a right-angled triangle, the side adjacent to a 67° angle is 16 m. Find the opposite side, to 1 decimal place.
Answer: 37.7 m
- tan 67° = opposite ÷ adjacent
- opposite = 16 × tan 67°
- ≈ 37.7
2.In a right-angled triangle, the hypotenuse is 8 cm and one angle is 33°. Find the side adjacent to the 33° angle, to 1 decimal place.
Answer: 6.7 cm
- cos 33° = adjacent ÷ hypotenuse
- adjacent = 8 × cos 33°
- ≈ 6.7
3.In a right-angled triangle, the hypotenuse is 28 cm and one angle is 57°. Find the side opposite the 57° angle, to 1 decimal place.
Answer: 23.5 cm
- sin 57° = opposite ÷ hypotenuse
- opposite = 28 × sin 57°
- ≈ 23.5
4.In a right-angled triangle, the hypotenuse is 30 cm and one angle is 24°. Find the side adjacent to the 24° angle, to 1 decimal place.
Answer: 27.4 cm
- cos 24° = adjacent ÷ hypotenuse
- adjacent = 30 × cos 24°
- ≈ 27.4
5.In a right-angled triangle, the side adjacent to a 38° angle is 22 m. Find the opposite side, to 1 decimal place.
Answer: 17.2 m
- tan 38° = opposite ÷ adjacent
- opposite = 22 × tan 38°
- ≈ 17.2
6.In a right-angled triangle, the hypotenuse is 6 cm and one angle is 44°. Find the side opposite the 44° angle, to 1 decimal place.
Answer: 4.2 cm
- sin 44° = opposite ÷ hypotenuse
- opposite = 6 × sin 44°
- ≈ 4.2
7.In a right-angled triangle, the side adjacent to a 25° angle is 16 m. Find the opposite side, to 1 decimal place.
Answer: 7.5 m
- tan 25° = opposite ÷ adjacent
- opposite = 16 × tan 25°
- ≈ 7.5
8.In a right-angled triangle, the hypotenuse is 25 cm and one angle is 49°. Find the side opposite the 49° angle, to 1 decimal place.
Answer: 18.9 cm
- sin 49° = opposite ÷ hypotenuse
- opposite = 25 × sin 49°
- ≈ 18.9
Marking tips
- Give credit for correct method even when the final answer slips — the working shows where the thinking went right.
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