Success TutoringWorksheets

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

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

1.In a right-angled triangle, the hypotenuse is 8 cm and one angle is 30°. Find the side opposite the 30° angle, to 1 decimal place.

Answer: 4 cm

  1. sin 30° = opposite ÷ hypotenuse
  2. opposite = 8 × sin 30°
  3. ≈ 4
2.In a right-angled triangle, the hypotenuse is 23 cm and one angle is 68°. Find the side opposite the 68° angle, to 1 decimal place.

Answer: 21.3 cm

  1. sin 68° = opposite ÷ hypotenuse
  2. opposite = 23 × sin 68°
  3. ≈ 21.3
3.In a right-angled triangle, the hypotenuse is 8 cm and one angle is 37°. Find the side opposite the 37° angle, to 1 decimal place.

Answer: 4.8 cm

  1. sin 37° = opposite ÷ hypotenuse
  2. opposite = 8 × sin 37°
  3. ≈ 4.8
4.In a right-angled triangle, the hypotenuse is 24 cm and one angle is 39°. Find the side opposite the 39° angle, to 1 decimal place.

Answer: 15.1 cm

  1. sin 39° = opposite ÷ hypotenuse
  2. opposite = 24 × sin 39°
  3. ≈ 15.1
5.In a right-angled triangle, the hypotenuse is 15 cm and one angle is 54°. Find the side opposite the 54° angle, to 1 decimal place.

Answer: 12.1 cm

  1. sin 54° = opposite ÷ hypotenuse
  2. opposite = 15 × sin 54°
  3. ≈ 12.1
6.In a right-angled triangle, the hypotenuse is 18 cm and one angle is 54°. Find the side opposite the 54° angle, to 1 decimal place.

Answer: 14.6 cm

  1. sin 54° = opposite ÷ hypotenuse
  2. opposite = 18 × sin 54°
  3. ≈ 14.6
7.In a right-angled triangle, the hypotenuse is 26 cm and one angle is 39°. Find the side opposite the 39° angle, to 1 decimal place.

Answer: 16.4 cm

  1. sin 39° = opposite ÷ hypotenuse
  2. opposite = 26 × sin 39°
  3. ≈ 16.4
8.In a right-angled triangle, the hypotenuse is 8 cm and one angle is 27°. Find the side opposite the 27° angle, to 1 decimal place.

Answer: 3.6 cm

  1. sin 27° = opposite ÷ hypotenuse
  2. opposite = 8 × sin 27°
  3. ≈ 3.6
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: