Triangle Calculator
From the two legs of a right triangle, find the hypotenuse, area, perimeter and angles.
Quick answer: enter your details below and click Calculate — your result appears instantly, right here in your browser. Nothing you enter is uploaded or stored.
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Calculators
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How to use
- Enter the first leg, side a.
- Enter the second leg, side b.
- Calculate to see the hypotenuse, area, perimeter and angles.
About this tool
Enter the two shorter sides of a right triangle, the legs that meet at the right angle. The tool uses Pythagoras to find the hypotenuse, halves the product of the legs for the area, adds all three sides for the perimeter, and uses inverse tangents to find both acute angles in degrees.
Frequently asked questions
Does this work for any triangle?
No. This tool is for right triangles only, where one angle is exactly 90 degrees and the two sides you enter meet at that angle.
Do the two angles add up to 90 degrees?
Yes. In a right triangle the two acute angles always add up to 90 degrees, since the third angle takes the other 90.