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Year 12 Trigonometry (Finding Sides) Worksheet — Level 1 — Answers

Answer sheet with worked solutions for the Year 12 trigonometry worksheet.

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Success TutoringWorksheetsAnswer sheetYear 12 · Mathematics · Trigonometry

Year 12 Trigonometry (Finding Sides) Worksheet — Level 1 — Answers

Label the sides (opposite, adjacent, hypotenuse), choose the ratio (SOH CAH TOA), then solve.

1.In a right-angled triangle, the hypotenuse is 12 cm and one angle is 66°. Find the side opposite the 66° angle, to 1 decimal place.

Answer: 11 cm

  1. sin 66° = opposite ÷ hypotenuse
  2. opposite = 12 × sin 66°
  3. ≈ 11
2.In a right-angled triangle, the hypotenuse is 13 cm and one angle is 25°. Find the side opposite the 25° angle, to 1 decimal place.

Answer: 5.5 cm

  1. sin 25° = opposite ÷ hypotenuse
  2. opposite = 13 × sin 25°
  3. ≈ 5.5
3.In a right-angled triangle, the hypotenuse is 11 cm and one angle is 39°. Find the side opposite the 39° angle, to 1 decimal place.

Answer: 6.9 cm

  1. sin 39° = opposite ÷ hypotenuse
  2. opposite = 11 × sin 39°
  3. ≈ 6.9
4.In a right-angled triangle, the hypotenuse is 13 cm and one angle is 22°. Find the side opposite the 22° angle, to 1 decimal place.

Answer: 4.9 cm

  1. sin 22° = opposite ÷ hypotenuse
  2. opposite = 13 × sin 22°
  3. ≈ 4.9
5.In a right-angled triangle, the hypotenuse is 11 cm and one angle is 57°. Find the side opposite the 57° angle, to 1 decimal place.

Answer: 9.2 cm

  1. sin 57° = opposite ÷ hypotenuse
  2. opposite = 11 × sin 57°
  3. ≈ 9.2
6.In a right-angled triangle, the hypotenuse is 22 cm and one angle is 38°. Find the side opposite the 38° angle, to 1 decimal place.

Answer: 13.5 cm

  1. sin 38° = opposite ÷ hypotenuse
  2. opposite = 22 × sin 38°
  3. ≈ 13.5
7.In a right-angled triangle, the hypotenuse is 9 cm and one angle is 36°. Find the side opposite the 36° angle, to 1 decimal place.

Answer: 5.3 cm

  1. sin 36° = opposite ÷ hypotenuse
  2. opposite = 9 × sin 36°
  3. ≈ 5.3
8.In a right-angled triangle, the hypotenuse is 20 cm and one angle is 23°. Find the side opposite the 23° angle, to 1 decimal place.

Answer: 7.8 cm

  1. sin 23° = opposite ÷ hypotenuse
  2. opposite = 20 × sin 23°
  3. ≈ 7.8
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