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Using Trigonometry to Find Side Lengths (Year 9)

Free printable NZ Year 9 maths worksheet: use given sine, cosine and tangent values to find unknown side lengths in right-angled triangles, rounded to 1 decimal place.

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Grade 8 · Math worksheet
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Math

Using Trigonometry to Find Side Lengths

Use the given trigonometric ratio to find the unknown side x in each right-angled triangle. Round each answer to 1 decimal place.

  1. 1.
    In the triangle shown, the angle theta = 55° and the hypotenuse is 28 cm. Using sin 55° ~ 0.819, find x, the length of the side opposite theta. Round your answer to 1 decimal place.
    θx28 cm
  2. 2.
    In the triangle shown, the angle theta = 60° and the hypotenuse is 14 cm. Using sin 60° ~ 0.866, find x, the length of the side opposite theta. Round your answer to 1 decimal place.
    θx14 cm
  3. 3.
    In the triangle shown, the angle theta = 60° and the hypotenuse is 22 cm. Using sin 60° ~ 0.866, find x, the length of the side opposite theta. Round your answer to 1 decimal place.
    θx22 cm
  4. 4.
    In the triangle shown, the angle theta = 40° and the hypotenuse is 27 cm. Using cos 40° ~ 0.766, find x, the length of the side adjacent to theta. Round your answer to 1 decimal place.
    θx27 cm
  5. 5.
    In the triangle shown, the angle theta = 40° and the hypotenuse is 29 cm. Using cos 40° ~ 0.766, find x, the length of the side adjacent to theta. Round your answer to 1 decimal place.
    θx29 cm
  6. 6.
    In the triangle shown, the angle theta = 40° and the hypotenuse is 12 cm. Using cos 40° ~ 0.766, find x, the length of the side adjacent to theta. Round your answer to 1 decimal place.
    θx12 cm
  7. 7.
    In the triangle shown, the angle theta = 60° and the side adjacent to theta is 17 cm. Using tan 60° ~ 1.732, find x, the length of the side opposite theta. Round your answer to 1 decimal place.
    θ17 cmx
  8. 8.
    In the triangle shown, the angle theta = 65° and the side adjacent to theta is 14 cm. Using tan 65° ~ 2.145, find x, the length of the side opposite theta. Round your answer to 1 decimal place.
    θ14 cmx
  9. 9.
    In the triangle shown, the angle theta = 40° and the side adjacent to theta is 13 cm. Using tan 40° ~ 0.839, find x, the length of the side opposite theta. Round your answer to 1 decimal place.
    θ13 cmx
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