📐 Geometry

Right Triangle Calculator

Solve a right triangle from one leg and an acute angle.

°

Results

Opposite leg
5.7735026919
Hypotenuse
11.5470053838
Area
28.8675134595

📊 Right Triangle Calculator chart

How the opposite leg changes as the angle θ varies. The orange dot marks your current value.

What is the Right Triangle Calculator?

Solve a right triangle from one leg and an acute angle. These geometry calculators work out area, perimeter, volume and surface area for common shapes. Units are flexible — enter every length in the same unit and the answer comes back in that unit (squared or cubed).

Right Triangle Calculator – free online geometry tool illustration
Right Triangle Calculator — free, exact and private.

How to use the Right Triangle Calculator

  1. Enter your adjacent leg, your angle θ.
  2. Results update automatically as you type; you can also press Calculate.
  3. Read the output: opposite leg, hypotenuse, area.
  4. Use the 📊 chart to see the result visually, then copy or share it.

Formula and method

opposite = adjacent × tan θ hypotenuse = adjacent ÷ cos θ

Worked example

With adjacent leg = 10, angle θ = 30 °, the Right Triangle Calculator returns opposite leg: 5.7735026919; hypotenuse: 11.5470053838; area: 28.8675134595.

Tips for better results

  • Keep all measurements in one unit before calculating.
  • Area units are squared (m², ft²) and volume units are cubed (m³, ft³).
  • Use our area and volume converters to switch units afterwards.

Frequently asked questions

What does the Right Triangle Calculator do?

Solve a right triangle from one leg and an acute angle.

How is it calculated?

The Right Triangle Calculator uses this method: opposite = adjacent × tan θ; hypotenuse = adjacent ÷ cos θ.

Can you show an example?

With adjacent leg = 10, angle θ = 30 °, the Right Triangle Calculator returns opposite leg: 5.7735026919; hypotenuse: 11.5470053838; area: 28.8675134595.

Is the Right Triangle Calculator accurate?

Yes. It uses standard formulas and exact constants, and the results are verified by our automated test suite. Values are displayed to up to 12 significant digits.

Is this tool free and private?

Yes — the Right Triangle Calculator is completely free with no sign-up, and it runs entirely in your browser, so the values you enter are never uploaded to our servers.

Related tools

📬 Get new tools first — free

Join Taurang to hear about new calculators, converters and features. No spam; unsubscribe anytime.

Create free account