Success TutoringWorksheets

Year 9 Trigonometry (Finding Sides) Worksheet — Level 1 — Answers

Answer sheet with worked solutions for the Year 9 trigonometry worksheet.

Download answers PDFPrint answersBack to worksheet

Year 9 · Mathematics · Trigonometry

Year 9 Trigonometry (Finding Sides) Worksheet — Level 1 — Answers

Success Tutoring

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

1.In a right-angled triangle, the hypotenuse is 13 cm and one angle is 64°. Find the side opposite the 64° angle, to 1 decimal place.

Answer: 11.7 cm

  1. sin 64° = opposite ÷ hypotenuse
  2. opposite = 13 × sin 64°
  3. ≈ 11.7
2.In a right-angled triangle, the hypotenuse is 9 cm and one angle is 50°. Find the side opposite the 50° angle, to 1 decimal place.

Answer: 6.9 cm

  1. sin 50° = opposite ÷ hypotenuse
  2. opposite = 9 × sin 50°
  3. ≈ 6.9
3.In a right-angled triangle, the hypotenuse is 28 cm and one angle is 25°. Find the side opposite the 25° angle, to 1 decimal place.

Answer: 11.8 cm

  1. sin 25° = opposite ÷ hypotenuse
  2. opposite = 28 × sin 25°
  3. ≈ 11.8
4.In a right-angled triangle, the hypotenuse is 13 cm and one angle is 51°. Find the side opposite the 51° angle, to 1 decimal place.

Answer: 10.1 cm

  1. sin 51° = opposite ÷ hypotenuse
  2. opposite = 13 × sin 51°
  3. ≈ 10.1
5.In a right-angled triangle, the hypotenuse is 16 cm and one angle is 57°. Find the side opposite the 57° angle, to 1 decimal place.

Answer: 13.4 cm

  1. sin 57° = opposite ÷ hypotenuse
  2. opposite = 16 × sin 57°
  3. ≈ 13.4
6.In a right-angled triangle, the hypotenuse is 21 cm and one angle is 34°. Find the side opposite the 34° angle, to 1 decimal place.

Answer: 11.7 cm

  1. sin 34° = opposite ÷ hypotenuse
  2. opposite = 21 × sin 34°
  3. ≈ 11.7
7.In a right-angled triangle, the hypotenuse is 18 cm and one angle is 63°. Find the side opposite the 63° angle, to 1 decimal place.

Answer: 16 cm

  1. sin 63° = opposite ÷ hypotenuse
  2. opposite = 18 × sin 63°
  3. ≈ 16
8.In a right-angled triangle, the hypotenuse is 14 cm and one angle is 57°. Find the side opposite the 57° angle, to 1 decimal place.

Answer: 11.7 cm

  1. sin 57° = opposite ÷ hypotenuse
  2. opposite = 14 × sin 57°
  3. ≈ 11.7
worksheets.successtutoring.com · Free to print and share 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.