Disclaimer: This app is for personal, casual, and hobby use. It is provided 'as-is' without warranties of accuracy; use for educational purposes is not intended.
gcse

GCSE trigonometry revision

Use this GCSE trigonometry page as a short revision guide before trying your own triangle problem in the solver tool.

Quick explanation

What this topic means and what to look for first.

GCSE trigonometry usually begins with right-angle triangle questions and SOHCAHTOA.

A good first check is to label opposite, adjacent, and hypotenuse before choosing a ratio.

Step-by-step method

One reliable route through the topic.

  1. 1Choose the angle you are working from.
  2. 2Label opposite, adjacent, and hypotenuse.
  3. 3Select sine, cosine, or tangent.
  4. 4Substitute the values carefully.
  5. 5Use inverse trig if you need the angle rather than a side.
Worked examples

See the method in action.

Example 1

Find x when sin 30 degrees = x / 12

  1. sin 30 degrees is 0.5.
  2. So x / 12 = 0.5.
  3. Therefore x = 6.
Example 2

Find theta when tan theta = 5 / 12

  1. Use the inverse tangent function.
  2. theta = tan^-1(5/12).
  3. So theta is about 22.6 degrees.
Common potential mistakes

Things that commonly send the method off track.

  • Choosing the wrong trig ratio because the sides were not labeled first.
  • Forgetting to use inverse trig when solving for an angle.
Follow-up access

Want to test your own problem next?

Use the public page first, then create a free account if you want to try the solver beta on a typed question or photo.

A free account is the current follow-up route for returning to the solver beta and future guide updates as the public library grows.

Follow-up access

Want to try a similar problem yourself?

Create a free account if you want to use the solver beta after reading the guide.

A free account is the current follow-up route for returning to the solver beta and future guide updates as the public library grows.

Share this page

Found this useful?

Share the page with someone who is searching for the same maths topic before they go straight to a solver.

FAQ

Short answers worth checking.

Do I need my calculator in degree mode?

Yes. For GCSE-style triangle problems, the calculator should usually be in degree mode.

What is the quickest way to remember the ratios?

Many students use SOHCAHTOA as a quick memory aid.

Related guides

Continue with the next closely related topic.

Next places to browse

Use the public site structure first, then switch into the solver tool only if you need a direct test.

CureMath uses artificial intelligence to suggest how a maths problem could potentially be solved. AI can make mistakes.

Check important answers independently before relying on them.