Success TutoringWorksheets

Year 11 Trigonometry (Finding Sides) Worksheet — Level 1 — Practice Set 4 — Answers

Answer sheet with worked solutions for the Year 11 trigonometry worksheet.

Download answers PDFPrint answersBack to worksheet
Success TutoringWorksheetsAnswer sheetYear 11 · Mathematics · Trigonometry

Year 11 Trigonometry (Finding Sides) Worksheet — Level 1 — Practice Set 4 — Answers

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

1.In a right-angled triangle, the hypotenuse is 15 cm and one angle is 26°. Find the side opposite the 26° angle, to 1 decimal place.

Answer: 6.6 cm

  1. sin 26° = opposite ÷ hypotenuse
  2. opposite = 15 × sin 26°
  3. ≈ 6.6
2.In a right-angled triangle, the hypotenuse is 30 cm and one angle is 29°. Find the side opposite the 29° angle, to 1 decimal place.

Answer: 14.5 cm

  1. sin 29° = opposite ÷ hypotenuse
  2. opposite = 30 × sin 29°
  3. ≈ 14.5
3.In a right-angled triangle, the hypotenuse is 25 cm and one angle is 54°. Find the side opposite the 54° angle, to 1 decimal place.

Answer: 20.2 cm

  1. sin 54° = opposite ÷ hypotenuse
  2. opposite = 25 × sin 54°
  3. ≈ 20.2
4.In a right-angled triangle, the hypotenuse is 23 cm and one angle is 60°. Find the side opposite the 60° angle, to 1 decimal place.

Answer: 19.9 cm

  1. sin 60° = opposite ÷ hypotenuse
  2. opposite = 23 × sin 60°
  3. ≈ 19.9
5.In a right-angled triangle, the hypotenuse is 18 cm and one angle is 66°. Find the side opposite the 66° angle, to 1 decimal place.

Answer: 16.4 cm

  1. sin 66° = opposite ÷ hypotenuse
  2. opposite = 18 × sin 66°
  3. ≈ 16.4
6.In a right-angled triangle, the hypotenuse is 23 cm and one angle is 69°. Find the side opposite the 69° angle, to 1 decimal place.

Answer: 21.5 cm

  1. sin 69° = opposite ÷ hypotenuse
  2. opposite = 23 × sin 69°
  3. ≈ 21.5
7.In a right-angled triangle, the hypotenuse is 18 cm and one angle is 51°. Find the side opposite the 51° angle, to 1 decimal place.

Answer: 14 cm

  1. sin 51° = opposite ÷ hypotenuse
  2. opposite = 18 × sin 51°
  3. ≈ 14
8.In a right-angled triangle, the hypotenuse is 9 cm and one angle is 38°. Find the side opposite the 38° angle, to 1 decimal place.

Answer: 5.5 cm

  1. sin 38° = opposite ÷ hypotenuse
  2. opposite = 9 × sin 38°
  3. ≈ 5.5
Free worksheets at worksheets.successtutoring.com · © Success Tutoring · Free for personal and classroom use

Marking tips

  • Give credit for correct method even when the final answer slips — the working shows where the thinking went right.
  • For open-ended tasks, use the success criteria as a checklist rather than looking for one "right" answer.
  • Celebrate what went well first, then pick one thing to work on next.

Great work. Here's what to try next: