Small practice. Bright discoveries.Explore the free starter collection
Back to worksheets
MathsAges 13-15

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.

New variationTry interactive challengeBrowse templates

Choose “Save as PDF” to keep a copy. Use your browser’s paper setting for A4 or Letter.

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 56 cm, the adjacent side is 192 cm, and the hypotenuse is 200 cm. Write cos(θ) as a simplified fraction.

    Opp = 56, Adj = 192, Hyp = 200 · Right Triangle → cos(θ)
  3. 3. 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 cos(θ) as a simplified fraction.

    Opp = 40, Adj = 75, Hyp = 85 · Right Triangle → cos(θ)
  4. 4. 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 cos(θ) as a simplified fraction.

    Opp = 9, Adj = 12, Hyp = 15 · Right Triangle → cos(θ)
  5. 5. In a right-angled triangle, the side opposite angle θ is 16 cm, the adjacent side is 30 cm, and the hypotenuse is 34 cm. Write tan(θ) as a simplified fraction.

    Opp = 16, Adj = 30, Hyp = 34 · Right Triangle → tan(θ)
  6. 6. 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 tan(θ) as a simplified fraction.

    Opp = 20, Adj = 48, Hyp = 52 · Right Triangle → tan(θ)
  7. 7. 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 cos(θ) as a simplified fraction.

    Opp = 21, Adj = 28, Hyp = 35 · Right Triangle → cos(θ)
  8. 8. 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 cos(θ) as a simplified fraction.

    Opp = 3, Adj = 4, Hyp = 5 · Right Triangle → cos(θ)
  9. 9. 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 cos(θ) as a simplified fraction.

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

    Opp = 18, Adj = 24, Hyp = 30 · Right Triangle → tan(θ)
  11. 11. In a right-angled triangle, the side opposite angle θ is 56 cm, the adjacent side is 192 cm, and the hypotenuse is 200 cm. Write tan(θ) as a simplified fraction.

    Opp = 56, Adj = 192, Hyp = 200 · Right Triangle → tan(θ)
  12. 12. 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 tan(θ) as a simplified fraction.

    Opp = 5, Adj = 12, Hyp = 13 · Right Triangle → tan(θ)
12 questions · Seed 55 · 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 56 cm, the adjacent side is 192 cm, and the hypotenuse is 200 cm. Write cos(θ) as a simplified fraction.

    24/25

    cos(θ) = adjacent ÷ hypotenuse = 192/200, which simplifies by dividing by 8 to 24/25.

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

    15/17

    cos(θ) = adjacent ÷ hypotenuse = 75/85, which simplifies by dividing by 5 to 15/17.

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

    4/5

    cos(θ) = adjacent ÷ hypotenuse = 12/15, which simplifies by dividing by 3 to 4/5.

  5. 5. In a right-angled triangle, the side opposite angle θ is 16 cm, the adjacent side is 30 cm, and the hypotenuse is 34 cm. Write tan(θ) as a simplified fraction.

    8/15

    tan(θ) = opposite ÷ adjacent = 16/30, which simplifies by dividing by 2 to 8/15.

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

    5/12

    tan(θ) = opposite ÷ adjacent = 20/48, which simplifies by dividing by 4 to 5/12.

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

    4/5

    cos(θ) = adjacent ÷ hypotenuse = 28/35, which simplifies by dividing by 7 to 4/5.

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

    4/5

    cos(θ) = adjacent ÷ hypotenuse = 4/5, which simplifies by dividing by 1 to 4/5.

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

    24/25

    cos(θ) = adjacent ÷ hypotenuse = 144/150, which simplifies by dividing by 6 to 24/25.

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

    3/4

    tan(θ) = opposite ÷ adjacent = 18/24, which simplifies by dividing by 6 to 3/4.

  11. 11. In a right-angled triangle, the side opposite angle θ is 56 cm, the adjacent side is 192 cm, and the hypotenuse is 200 cm. Write tan(θ) as a simplified fraction.

    7/24

    tan(θ) = opposite ÷ adjacent = 56/192, which simplifies by dividing by 8 to 7/24.

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

    5/12

    tan(θ) = opposite ÷ adjacent = 5/12, which simplifies by dividing by 1 to 5/12.

12 questions · Seed 55 · Age guidance, not curriculum certification