Worksheets · Algebra 1

Algebra 1 right triangle trigonometry worksheet

The ratios come from whole-number sides, so they come out exact, and so do the missing sides from a special angle. The calculator questions, a side from any angle or an angle from two sides, round to the tenth or the degree.

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Pick more than one for a sheet that mixes them.

Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep

Sigma Prep · sigmaprep.io/worksheets

Name

Right Triangle Trigonometry

Date Period

Answer each question.

  1. A right triangle has legs 15 and 8 and hypotenuse 17. Find sin⁡A, where A is opposite the side of length 15
  2. A right triangle has legs 120 and 126 and hypotenuse 174. Find cos⁡A, where A is opposite the side of length 120
  3. A right triangle has legs 32 and 60 and hypotenuse 68. Find tan⁡A, where A is opposite the side of length 32
  4. A right triangle has hypotenuse 32 and an angle of 60∘. Find the side opposite it
  5. A right triangle has legs 9 and 12 and hypotenuse 15. Find sin⁡A, where A is opposite the side of length 9
  6. A right triangle has legs 9 and 12 and hypotenuse 15. Find cos⁡A, where A is opposite the side of length 9
  7. A right triangle has legs 20 and 48 and hypotenuse 52. Find tan⁡A, where A is opposite the side of length 20
  8. A right triangle has hypotenuse 22 and an angle of 30∘. Find the side opposite it
  9. A right triangle has legs 32 and 60 and hypotenuse 68. Find sin⁡A, where A is opposite the side of length 32
  10. A right triangle has legs 48 and 20 and hypotenuse 52. Find cos⁡A, where A is opposite the side of length 48
  11. A right triangle has legs 24 and 7 and hypotenuse 25. Find tan⁡A, where A is opposite the side of length 24
  12. A right triangle has hypotenuse 40 and an angle of 45∘. Find the side adjacent to it
  13. A right triangle has legs 12 and 16 and hypotenuse 20. Find sin⁡A, where A is opposite the side of length 12
  14. A right triangle has legs 15 and 36 and hypotenuse 39. Find cos⁡A, where A is opposite the side of length 15
  15. A right triangle has legs 16 and 12 and hypotenuse 20. Find tan⁡A, where A is opposite the side of length 16
  16. A right triangle has hypotenuse 28 and an angle of 30∘. Find the side opposite it
  17. A right triangle has legs 40 and 75 and hypotenuse 85. Find sin⁡A, where A is opposite the side of length 40
  18. A right triangle has legs 100 and 105 and hypotenuse 145. Find cos⁡A, where A is opposite the side of length 100
  19. A right triangle has legs 48 and 20 and hypotenuse 52. Find tan⁡A, where A is opposite the side of length 48
  20. A right triangle has hypotenuse 38 and an angle of 60∘. Find the side adjacent to it

Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep

Sigma Prep · sigmaprep.io/worksheets

Name

Right Triangle TrigonometryAnswer keyVersion 1

Date Period

Answer each question.

  1. A right triangle has legs 15 and 8 and hypotenuse 17. Find sin⁡A, where A is opposite the side of length 151517
  2. A right triangle has legs 120 and 126 and hypotenuse 174. Find cos⁡A, where A is opposite the side of length 1202129
  3. A right triangle has legs 32 and 60 and hypotenuse 68. Find tan⁡A, where A is opposite the side of length 32815
  4. A right triangle has hypotenuse 32 and an angle of 60∘. Find the side opposite it163
  5. A right triangle has legs 9 and 12 and hypotenuse 15. Find sin⁡A, where A is opposite the side of length 935
  6. A right triangle has legs 9 and 12 and hypotenuse 15. Find cos⁡A, where A is opposite the side of length 945
  7. A right triangle has legs 20 and 48 and hypotenuse 52. Find tan⁡A, where A is opposite the side of length 20512
  8. A right triangle has hypotenuse 22 and an angle of 30∘. Find the side opposite it11
  9. A right triangle has legs 32 and 60 and hypotenuse 68. Find sin⁡A, where A is opposite the side of length 32817
  10. A right triangle has legs 48 and 20 and hypotenuse 52. Find cos⁡A, where A is opposite the side of length 48513
  11. A right triangle has legs 24 and 7 and hypotenuse 25. Find tan⁡A, where A is opposite the side of length 24247
  12. A right triangle has hypotenuse 40 and an angle of 45∘. Find the side adjacent to it202
  13. A right triangle has legs 12 and 16 and hypotenuse 20. Find sin⁡A, where A is opposite the side of length 1235
  14. A right triangle has legs 15 and 36 and hypotenuse 39. Find cos⁡A, where A is opposite the side of length 151213
  15. A right triangle has legs 16 and 12 and hypotenuse 20. Find tan⁡A, where A is opposite the side of length 1643
  16. A right triangle has hypotenuse 28 and an angle of 30∘. Find the side opposite it14
  17. A right triangle has legs 40 and 75 and hypotenuse 85. Find sin⁡A, where A is opposite the side of length 40817
  18. A right triangle has legs 100 and 105 and hypotenuse 145. Find cos⁡A, where A is opposite the side of length 1002129
  19. A right triangle has legs 48 and 20 and hypotenuse 52. Find tan⁡A, where A is opposite the side of length 48125
  20. A right triangle has hypotenuse 38 and an angle of 60∘. Find the side adjacent to it19

Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep

How to do these

A right triangle has legs 3 and 4 and hypotenuse 5. Find sin⁡A, where A is opposite the side of length 3

  1. Sine is opposite over hypotenuse.
  2. The side opposite A is 3, and the hypotenuse is 5.

The answer is 35.

Where students go wrong

Using the hypotenuse as the adjacent side. The hypotenuse is never the adjacent one: adjacent means the leg next to the angle, and the hypotenuse has its own name for a reason.

Also called SOHCAHTOA, trig ratios or finding missing sides.

What you can put on this worksheet

Sine from the three sides
A right triangle has legs 45 and 24 and hypotenuse 51. Find sin⁡A, where A is opposite the side of length 45 → 1517
Cosine from the three sides
A right triangle has legs 45 and 24 and hypotenuse 51. Find cos⁡A, where A is opposite the side of length 45 → 817
Tangent from the three sides
A right triangle has legs 45 and 24 and hypotenuse 51. Find tan⁡A, where A is opposite the side of length 45 → 158
A missing side from a special angle
A right triangle has hypotenuse 12 and an angle of 45∘. Find the side adjacent to it → 62
Cosecant, secant and cotangent from the sides
A right triangle has legs 45 and 24 and hypotenuse 51. Find csc⁡A, where A is opposite the side of length 45 → 1715
A missing side, any angle, rounded
Find x. Round to the nearest tenth. → 13.9
An angle from two sides, with inverse trig
Find θ. Round to the nearest degree. → 33∘

Questions about these worksheets

Yes. Every right triangle trigonometry sheet is free to print and free to download as a PDF. There is no account to make, no email to hand over and no limit on how many you take.

Yes. The answer key prints on a second page, and you can choose whether it shows each question beside its answer or just the answers in a list.

Yes. Print straight from the page, or download the PDF and print that. The sheet is laid out for paper rather than squeezed off a screen, so there is room to work under each question, and the answer key comes out on its own page.

Algebra 1 is usually taken around 8th or 9th grade, though schools vary and plenty of students meet it earlier or later. Pick the difficulty rather than the grade: the easy level suits a first lesson on it, the hard level suits review before a test.

Yes, as many as you like. The questions are built fresh each time rather than picked from a fixed set of files, so pressing Generate gives a new sheet. That is what you want for a second class, a retake, or two students sitting next to each other.

That is the closest comparison, and Kuta Software is good software. It is also paid software you install on a computer. These worksheets run in a browser tab for free, with no account and nothing to install. Like Kuta, the right triangle trigonometry questions are generated when you ask for them rather than pulled from a fixed set of files, so two classes never get the same sheet, and the answer key comes with it.

Yes. There are two levels, and you can tick more than one for a sheet that mixes them, in which case the questions come out easiest first. The harder levels are not just larger numbers: they ask for something the easy ones do not.

You pick from 7: sine from the three sides, cosine from the three sides, tangent from the three sides, a missing side from a special angle, cosecant, secant and cotangent from the sides, a missing side, any angle, rounded and an angle from two sides, with inverse trig. Tick as many as you want and set how many of each, or let it spread them evenly.

Using the hypotenuse as the adjacent side. The hypotenuse is never the adjacent one: adjacent means the leg next to the angle, and the hypotenuse has its own name for a reason.