Geometry & Measurement Calculators
Triangle Inradius Calculator
Find the radius of a triangle's inscribed circle from its sides.
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What is Triangle Inradius?
The inradius is the radius of the largest circle that fits inside the triangle, tangent to all three sides.
How it works
We find the area with Heron's formula and divide by the semi-perimeter: r = K/s. The equality K = rs is one of the neatest area identities.
- Enter your input. Type or paste your input into the field above — the tool responds instantly.
- Review the result. Output updates live as you type. Everything runs entirely in your browser.
- Copy or download. Use the Copy button to grab the result, or Download to save it as a file.
Examples
Realistic sample
Type or paste any realistic input — the tool computes the result locally and instantly.
Common mistakes
Expecting a server round-trip
Nothing is uploaded — every tool in this category runs entirely in your browser.