Mathematics · Trigonometry

Right Triangle Calculator

Solve a right triangle from its two perpendicular legs.

Runs locally

Inputs and results stay in this browser. Change one value at a time to explore the relationship.

Hypotenuse5
Angle A36.869898

degrees

Angle B53.130102

degrees

Calculation steps

  1. Hypotenuse = √(3² + 4²) = 5.
  2. Angle A = arctan(3 ÷ 4) = 36.86989764584402°.
  3. Angle B = 90° − 36.86989764584402° = 53.13010235415598°.

Definition and formula

The Pythagorean theorem gives the hypotenuse and inverse tangent converts the side ratio into an acute angle.

c = √(a² + b²); angle A = arctan(a ÷ b)

Worked example

Legs 3 and 4 produce hypotenuse 5 and acute angles about 36.87° and 53.13°.

Common mistake

Calculator trigonometric functions may use radians; this tool reports degrees.

How to learn with this calculator

Begin with the worked example, then change one value while keeping the others fixed. Compare the new result and calculation steps to identify which part of the formula changed.

Clear answers

Frequently asked questions

What does the Right triangle do?

Solve a right triangle from its two perpendicular legs.

How does the Right triangle work?

The calculator applies c = √(a² + b²); angle A = arctan(a ÷ b). The Pythagorean theorem gives the hypotenuse and inverse tangent converts the side ratio into an acute angle.

What can I learn from the Right triangle?

It connects the mathematical rule to your chosen numbers and shows each calculation step. Change one input at a time to see how the result responds.

Does MW SysArc receive or store what I enter?

No. The calculation runs locally in your browser. MW SysArc does not receive or store your calculation inputs.

How should I use the result?

Use the steps to understand the method, then verify important school or professional work using the notation and rounding rules required in your setting.

Last reviewed 2026-07-14. Calculations tested 2026-07-14.