Triangle Hypotenuse Calculator

Enter Triangle Values

Example Data Table

Leg A	Leg B	Hypotenuse	Area	Perimeter	Angles
3 cm	4 cm	5 cm	6 cm²	12 cm	36.87°, 53.13°
5 m	12 m	13 m	30 m²	30 m	22.62°, 67.38°
8 in	15 in	17 in	60 in²	40 in	28.07°, 61.93°

Formula Used

Hypotenuse:
c = √(a² + b²)

Area:
Area = (a × b) / 2

Perimeter:
Perimeter = a + b + c

Angles:
α = tan^-1(a / b), β = tan^-1(b / a)

Altitude to Hypotenuse:
h = (a × b) / c

Inradius and Circumradius:
r = (a + b - c) / 2, R = c / 2

This calculator uses the Pythagorean theorem for the main diagonal length, then derives additional right-triangle measures from standard geometry relationships.

How to Use This Calculator

Enter the first perpendicular side in the Leg A field.
Enter the second perpendicular side in the Leg B field.
Add a unit label such as cm, m, ft, or in.
Select how many decimal places you want to display.
Click Calculate Hypotenuse to generate the result block.
Review the hypotenuse, angles, perimeter, area, and derived values.
Use the CSV button for spreadsheet export.
Use the PDF button to save a printable copy.

Frequently Asked Questions

1. What does this calculator solve?

It finds the hypotenuse of a right triangle from two known legs. It also calculates area, perimeter, acute angles, altitude to the hypotenuse, inradius, circumradius, and a validation check for the theorem.

2. When should I use it?

Use it in geometry homework, drafting, construction layouts, machining, truss design, navigation sketches, and any situation where two perpendicular sides are known and the diagonal is required.

3. Does it work for any triangle?

No. This page is built for right triangles only. The two inputs must represent perpendicular sides that meet at a 90-degree angle.

4. Why are there two angle results?

Every right triangle has two acute angles in addition to the fixed 90-degree angle. The calculator returns both complementary acute angles, and their sum always equals 90 degrees.

5. Can I use decimals and custom units?

Yes. Decimal values are supported, and the unit field accepts custom labels such as mm, cm, m, in, ft, or any practical measurement tag you prefer.

6. What is the Pythagorean check?

It shows that c² matches a² + b² using your entered values. This helps confirm the computed hypotenuse and makes the output easier to review or report.

7. What does the graph represent?

The Plotly graph draws the right triangle using your two legs. It visually confirms the geometry and helps compare the diagonal against the horizontal and vertical sides.

8. Can I save the result for reports?

Yes. You can download a CSV file for data handling and a PDF for sharing, printing, or keeping a fixed copy of the result summary and chart.