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Right-triangle trigonometry (SOHCAHTOA)

Apply sine, cosine and tangent ratios (SOHCAHTOA) in right-angled triangles and simplify to lowest terms. Review suitability for your learners before teaching.

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Worksheet StudioPractice pack · Ages 16-18

Right-triangle trigonometry (SOHCAHTOA)

Take your time. Show your thinking.

  1. 1. In a right-angled triangle, the side opposite angle θ is 30 cm, the adjacent side is 72 cm, and the hypotenuse is 78 cm. Write sin(θ) as a simplified fraction.

    Opp = 30, Adj = 72, Hyp = 78 · Right Triangle → sin(θ)
  2. 2. In a right-angled triangle, the side opposite angle θ is 21 cm, the adjacent side is 72 cm, and the hypotenuse is 75 cm. Write tan(θ) as a simplified fraction.

    Opp = 21, Adj = 72, Hyp = 75 · Right Triangle → tan(θ)
  3. 3. In a right-angled triangle, the side opposite angle θ is 6 cm, the adjacent side is 8 cm, and the hypotenuse is 10 cm. Write sin(θ) as a simplified fraction.

    Opp = 6, Adj = 8, Hyp = 10 · Right Triangle → sin(θ)
  4. 4. In a right-angled triangle, the side opposite angle θ is 12 cm, the adjacent side is 16 cm, and the hypotenuse is 20 cm. Write tan(θ) as a simplified fraction.

    Opp = 12, Adj = 16, Hyp = 20 · Right Triangle → tan(θ)
  5. 5. In a right-angled triangle, the side opposite angle θ is 12 cm, the adjacent side is 16 cm, and the hypotenuse is 20 cm. Write cos(θ) as a simplified fraction.

    Opp = 12, Adj = 16, Hyp = 20 · Right Triangle → cos(θ)
  6. 6. In a right-angled triangle, the side opposite angle θ is 21 cm, the adjacent side is 28 cm, and the hypotenuse is 35 cm. Write sin(θ) as a simplified fraction.

    Opp = 21, Adj = 28, Hyp = 35 · Right Triangle → sin(θ)
  7. 7. In a right-angled triangle, the side opposite angle θ is 24 cm, the adjacent side is 32 cm, and the hypotenuse is 40 cm. Write sin(θ) as a simplified fraction.

    Opp = 24, Adj = 32, Hyp = 40 · Right Triangle → sin(θ)
  8. 8. In a right-angled triangle, the side opposite angle θ is 10 cm, the adjacent side is 24 cm, and the hypotenuse is 26 cm. Write sin(θ) as a simplified fraction.

    Opp = 10, Adj = 24, Hyp = 26 · Right Triangle → sin(θ)
  9. 9. In a right-angled triangle, the side opposite angle θ is 5 cm, the adjacent side is 12 cm, and the hypotenuse is 13 cm. Write cos(θ) as a simplified fraction.

    Opp = 5, Adj = 12, Hyp = 13 · Right Triangle → cos(θ)
  10. 10. In a right-angled triangle, the side opposite angle θ is 25 cm, the adjacent side is 60 cm, and the hypotenuse is 65 cm. Write cos(θ) as a simplified fraction.

    Opp = 25, Adj = 60, Hyp = 65 · Right Triangle → cos(θ)
  11. 11. In a right-angled triangle, the side opposite angle θ is 40 cm, the adjacent side is 96 cm, and the hypotenuse is 104 cm. Write sin(θ) as a simplified fraction.

    Opp = 40, Adj = 96, Hyp = 104 · Right Triangle → sin(θ)
  12. 12. In a right-angled triangle, the side opposite angle θ is 28 cm, the adjacent side is 96 cm, and the hypotenuse is 100 cm. Write tan(θ) as a simplified fraction.

    Opp = 28, Adj = 96, Hyp = 100 · Right Triangle → tan(θ)
12 questions · Seed 43 · Age guidance, not curriculum certification
View the answer key
Worksheet StudioAnswer key · Ages 16-18

Right-triangle trigonometry (SOHCAHTOA)

Answers and reasoning. Review before teaching.

  1. 1. In a right-angled triangle, the side opposite angle θ is 30 cm, the adjacent side is 72 cm, and the hypotenuse is 78 cm. Write sin(θ) as a simplified fraction.

    5/13

    sin(θ) = opposite ÷ hypotenuse = 30/78, which simplifies by dividing by 6 to 5/13.

  2. 2. In a right-angled triangle, the side opposite angle θ is 21 cm, the adjacent side is 72 cm, and the hypotenuse is 75 cm. Write tan(θ) as a simplified fraction.

    7/24

    tan(θ) = opposite ÷ adjacent = 21/72, which simplifies by dividing by 3 to 7/24.

  3. 3. In a right-angled triangle, the side opposite angle θ is 6 cm, the adjacent side is 8 cm, and the hypotenuse is 10 cm. Write sin(θ) as a simplified fraction.

    3/5

    sin(θ) = opposite ÷ hypotenuse = 6/10, which simplifies by dividing by 2 to 3/5.

  4. 4. In a right-angled triangle, the side opposite angle θ is 12 cm, the adjacent side is 16 cm, and the hypotenuse is 20 cm. Write tan(θ) as a simplified fraction.

    3/4

    tan(θ) = opposite ÷ adjacent = 12/16, which simplifies by dividing by 4 to 3/4.

  5. 5. In a right-angled triangle, the side opposite angle θ is 12 cm, the adjacent side is 16 cm, and the hypotenuse is 20 cm. Write cos(θ) as a simplified fraction.

    4/5

    cos(θ) = adjacent ÷ hypotenuse = 16/20, which simplifies by dividing by 4 to 4/5.

  6. 6. In a right-angled triangle, the side opposite angle θ is 21 cm, the adjacent side is 28 cm, and the hypotenuse is 35 cm. Write sin(θ) as a simplified fraction.

    3/5

    sin(θ) = opposite ÷ hypotenuse = 21/35, which simplifies by dividing by 7 to 3/5.

  7. 7. In a right-angled triangle, the side opposite angle θ is 24 cm, the adjacent side is 32 cm, and the hypotenuse is 40 cm. Write sin(θ) as a simplified fraction.

    3/5

    sin(θ) = opposite ÷ hypotenuse = 24/40, which simplifies by dividing by 8 to 3/5.

  8. 8. In a right-angled triangle, the side opposite angle θ is 10 cm, the adjacent side is 24 cm, and the hypotenuse is 26 cm. Write sin(θ) as a simplified fraction.

    5/13

    sin(θ) = opposite ÷ hypotenuse = 10/26, which simplifies by dividing by 2 to 5/13.

  9. 9. In a right-angled triangle, the side opposite angle θ is 5 cm, the adjacent side is 12 cm, and the hypotenuse is 13 cm. Write cos(θ) as a simplified fraction.

    12/13

    cos(θ) = adjacent ÷ hypotenuse = 12/13, which simplifies by dividing by 1 to 12/13.

  10. 10. In a right-angled triangle, the side opposite angle θ is 25 cm, the adjacent side is 60 cm, and the hypotenuse is 65 cm. Write cos(θ) as a simplified fraction.

    12/13

    cos(θ) = adjacent ÷ hypotenuse = 60/65, which simplifies by dividing by 5 to 12/13.

  11. 11. In a right-angled triangle, the side opposite angle θ is 40 cm, the adjacent side is 96 cm, and the hypotenuse is 104 cm. Write sin(θ) as a simplified fraction.

    5/13

    sin(θ) = opposite ÷ hypotenuse = 40/104, which simplifies by dividing by 8 to 5/13.

  12. 12. In a right-angled triangle, the side opposite angle θ is 28 cm, the adjacent side is 96 cm, and the hypotenuse is 100 cm. Write tan(θ) as a simplified fraction.

    7/24

    tan(θ) = opposite ÷ adjacent = 28/96, which simplifies by dividing by 4 to 7/24.

12 questions · Seed 43 · Age guidance, not curriculum certification