±Free
Triangle from three sides
Calculate area, perimeter and angles from three valid side lengths.
Enter three positive side lengths in one common unit. The tool checks that they form a triangle, computes Heron’s area and perimeter, and returns the angles opposite the supplied sides in degrees.
How to use
- Enter your text, values, or image.
- Adjust the options and run the tool.
- Copy or download your result.
Worked example
Example input
Side a: 3 Side b: 4 Side c: 5
Example result
{
"area": 6,
"perimeter": 12,
"angles": [
36.8698976458,
53.1301023542,
90
]
}Limitations and details
Sides must satisfy the strict triangle inequality; nearly degenerate triangles may be sensitive to floating-point rounding.
Inputs and options
- Side a
- Number
- Side b
- Number
- Side c
- Number
Frequently asked questions
Is this tool free and private?
Yes. All 300 tools are free in this phase. Processing happens in your browser; your input and files are not sent to our servers.