Every triangle here has whole-number sides, so the ratios come out exact, and every angle is a special one, so the missing sides do too. No calculator anywhere.
A right triangle has legs 3 and 4 and hypotenuse 5. Find sinA, where A is opposite the side of length 3
Sine is opposite over hypotenuse.
The side opposite A is 3, and the hypotenuse is 5.
The answer is 53.
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 sinA, where A is opposite the side of length 45→ 1715
Cosine from the three sides
A right triangle has legs 45 and 24 and hypotenuse 51. Find cosA, where A is opposite the side of length 45→ 178
Tangent from the three sides
A right triangle has legs 45 and 24 and hypotenuse 51. Find tanA, where A is opposite the side of length 45→ 815
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
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.
Geometry is usually taken around 9th or 10th 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 4: sine from the three sides, cosine from the three sides, tangent from the three sides and a missing side from a special angle. 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.