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Year 9 Trigonometry (Finding Sides) Worksheet — Level 3 — Practice Set 4 — Answers

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

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Success TutoringWorksheetsAnswer sheetYear 9 · Mathematics · Trigonometry

Year 9 Trigonometry (Finding Sides) Worksheet — Level 3 — 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 side adjacent to a 30° angle is 6 m. Find the opposite side, to 1 decimal place.

Answer: 3.5 m

  1. tan 30° = opposite ÷ adjacent
  2. opposite = 6 × tan 30°
  3. ≈ 3.5
2.In a right-angled triangle, the side adjacent to a 29° angle is 15 m. Find the opposite side, to 1 decimal place.

Answer: 8.3 m

  1. tan 29° = opposite ÷ adjacent
  2. opposite = 15 × tan 29°
  3. ≈ 8.3
3.In a right-angled triangle, the hypotenuse is 27 cm and one angle is 47°. Find the side adjacent to the 47° angle, to 1 decimal place.

Answer: 18.4 cm

  1. cos 47° = adjacent ÷ hypotenuse
  2. adjacent = 27 × cos 47°
  3. ≈ 18.4
4.In a right-angled triangle, the hypotenuse is 6 cm and one angle is 26°. Find the side adjacent to the 26° angle, to 1 decimal place.

Answer: 5.4 cm

  1. cos 26° = adjacent ÷ hypotenuse
  2. adjacent = 6 × cos 26°
  3. ≈ 5.4
5.In a right-angled triangle, the side adjacent to a 31° angle is 8 m. Find the opposite side, to 1 decimal place.

Answer: 4.8 m

  1. tan 31° = opposite ÷ adjacent
  2. opposite = 8 × tan 31°
  3. ≈ 4.8
6.In a right-angled triangle, the hypotenuse is 20 cm and one angle is 34°. Find the side adjacent to the 34° angle, to 1 decimal place.

Answer: 16.6 cm

  1. cos 34° = adjacent ÷ hypotenuse
  2. adjacent = 20 × cos 34°
  3. ≈ 16.6
7.In a right-angled triangle, the hypotenuse is 19 cm and one angle is 59°. Find the side adjacent to the 59° angle, to 1 decimal place.

Answer: 9.8 cm

  1. cos 59° = adjacent ÷ hypotenuse
  2. adjacent = 19 × cos 59°
  3. ≈ 9.8
8.In a right-angled triangle, the hypotenuse is 9 cm and one angle is 23°. Find the side adjacent to the 23° angle, to 1 decimal place.

Answer: 8.3 cm

  1. cos 23° = adjacent ÷ hypotenuse
  2. adjacent = 9 × cos 23°
  3. ≈ 8.3
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