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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 13-15

Right-triangle trigonometry (SOHCAHTOA)

Take your time. Show your thinking.

  1. 1. In a right-angled triangle, the side opposite angle θ is 9 cm, the adjacent side is 12 cm, and the hypotenuse is 15 cm. Write sin(θ) as a simplified fraction.

    Opp = 9, Adj = 12, Hyp = 15 · Right Triangle → sin(θ)
  2. 2. In a right-angled triangle, the side opposite angle θ is 40 cm, the adjacent side is 75 cm, and the hypotenuse is 85 cm. Write sin(θ) as a simplified fraction.

    Opp = 40, Adj = 75, Hyp = 85 · Right Triangle → sin(θ)
  3. 3. In a right-angled triangle, the side opposite angle θ is 3 cm, the adjacent side is 4 cm, and the hypotenuse is 5 cm. Write sin(θ) as a simplified fraction.

    Opp = 3, Adj = 4, Hyp = 5 · Right Triangle → sin(θ)
  4. 4. In a right-angled triangle, the side opposite angle θ is 20 cm, the adjacent side is 48 cm, and the hypotenuse is 52 cm. Write sin(θ) as a simplified fraction.

    Opp = 20, Adj = 48, Hyp = 52 · Right Triangle → sin(θ)
  5. 5. In a right-angled triangle, the side opposite angle θ is 24 cm, the adjacent side is 45 cm, and the hypotenuse is 51 cm. Write tan(θ) as a simplified fraction.

    Opp = 24, Adj = 45, Hyp = 51 · Right Triangle → tan(θ)
  6. 6. In a right-angled triangle, the side opposite angle θ is 32 cm, the adjacent side is 60 cm, and the hypotenuse is 68 cm. Write tan(θ) as a simplified fraction.

    Opp = 32, Adj = 60, Hyp = 68 · Right Triangle → tan(θ)
  7. 7. In a right-angled triangle, the side opposite angle θ is 64 cm, the adjacent side is 120 cm, and the hypotenuse is 136 cm. Write cos(θ) as a simplified fraction.

    Opp = 64, Adj = 120, Hyp = 136 · Right Triangle → cos(θ)
  8. 8. In a right-angled triangle, the side opposite angle θ is 42 cm, the adjacent side is 144 cm, and the hypotenuse is 150 cm. Write sin(θ) as a simplified fraction.

    Opp = 42, Adj = 144, Hyp = 150 · Right Triangle → sin(θ)
  9. 9. 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 tan(θ) as a simplified fraction.

    Opp = 6, Adj = 8, Hyp = 10 · Right Triangle → tan(θ)
  10. 10. In a right-angled triangle, the side opposite angle θ is 42 cm, the adjacent side is 144 cm, and the hypotenuse is 150 cm. Write tan(θ) as a simplified fraction.

    Opp = 42, Adj = 144, Hyp = 150 · Right Triangle → tan(θ)
  11. 11. In a right-angled triangle, the side opposite angle θ is 18 cm, the adjacent side is 24 cm, and the hypotenuse is 30 cm. Write cos(θ) as a simplified fraction.

    Opp = 18, Adj = 24, Hyp = 30 · Right Triangle → cos(θ)
  12. 12. 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 cos(θ) as a simplified fraction.

    Opp = 6, Adj = 8, Hyp = 10 · Right Triangle → cos(θ)
12 questions · Seed 52 · Age guidance, not curriculum certification
View the answer key
Worksheet StudioAnswer key · Ages 13-15

Right-triangle trigonometry (SOHCAHTOA)

Answers and reasoning. Review before teaching.

  1. 1. In a right-angled triangle, the side opposite angle θ is 9 cm, the adjacent side is 12 cm, and the hypotenuse is 15 cm. Write sin(θ) as a simplified fraction.

    3/5

    sin(θ) = opposite ÷ hypotenuse = 9/15, which simplifies by dividing by 3 to 3/5.

  2. 2. In a right-angled triangle, the side opposite angle θ is 40 cm, the adjacent side is 75 cm, and the hypotenuse is 85 cm. Write sin(θ) as a simplified fraction.

    8/17

    sin(θ) = opposite ÷ hypotenuse = 40/85, which simplifies by dividing by 5 to 8/17.

  3. 3. In a right-angled triangle, the side opposite angle θ is 3 cm, the adjacent side is 4 cm, and the hypotenuse is 5 cm. Write sin(θ) as a simplified fraction.

    3/5

    sin(θ) = opposite ÷ hypotenuse = 3/5, which simplifies by dividing by 1 to 3/5.

  4. 4. In a right-angled triangle, the side opposite angle θ is 20 cm, the adjacent side is 48 cm, and the hypotenuse is 52 cm. Write sin(θ) as a simplified fraction.

    5/13

    sin(θ) = opposite ÷ hypotenuse = 20/52, which simplifies by dividing by 4 to 5/13.

  5. 5. In a right-angled triangle, the side opposite angle θ is 24 cm, the adjacent side is 45 cm, and the hypotenuse is 51 cm. Write tan(θ) as a simplified fraction.

    8/15

    tan(θ) = opposite ÷ adjacent = 24/45, which simplifies by dividing by 3 to 8/15.

  6. 6. In a right-angled triangle, the side opposite angle θ is 32 cm, the adjacent side is 60 cm, and the hypotenuse is 68 cm. Write tan(θ) as a simplified fraction.

    8/15

    tan(θ) = opposite ÷ adjacent = 32/60, which simplifies by dividing by 4 to 8/15.

  7. 7. In a right-angled triangle, the side opposite angle θ is 64 cm, the adjacent side is 120 cm, and the hypotenuse is 136 cm. Write cos(θ) as a simplified fraction.

    15/17

    cos(θ) = adjacent ÷ hypotenuse = 120/136, which simplifies by dividing by 8 to 15/17.

  8. 8. In a right-angled triangle, the side opposite angle θ is 42 cm, the adjacent side is 144 cm, and the hypotenuse is 150 cm. Write sin(θ) as a simplified fraction.

    7/25

    sin(θ) = opposite ÷ hypotenuse = 42/150, which simplifies by dividing by 6 to 7/25.

  9. 9. 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 tan(θ) as a simplified fraction.

    3/4

    tan(θ) = opposite ÷ adjacent = 6/8, which simplifies by dividing by 2 to 3/4.

  10. 10. In a right-angled triangle, the side opposite angle θ is 42 cm, the adjacent side is 144 cm, and the hypotenuse is 150 cm. Write tan(θ) as a simplified fraction.

    7/24

    tan(θ) = opposite ÷ adjacent = 42/144, which simplifies by dividing by 6 to 7/24.

  11. 11. In a right-angled triangle, the side opposite angle θ is 18 cm, the adjacent side is 24 cm, and the hypotenuse is 30 cm. Write cos(θ) as a simplified fraction.

    4/5

    cos(θ) = adjacent ÷ hypotenuse = 24/30, which simplifies by dividing by 6 to 4/5.

  12. 12. 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 cos(θ) as a simplified fraction.

    4/5

    cos(θ) = adjacent ÷ hypotenuse = 8/10, which simplifies by dividing by 2 to 4/5.

12 questions · Seed 52 · Age guidance, not curriculum certification