Triangle Area Calculator
Calculate triangle area from 3 sides using Heron's formula.
About this tool
Calculate the area of any triangle from its three side lengths using Heron's formula \u2014 no need to know the height, which makes this useful for triangles that aren't right triangles.
Key Features
- Works for any triangle shape, not just right triangles
- Uses Heron's formula (no height needed)
- Validates that the three sides can actually form a triangle
How to Use
- Enter the three side lengths.
- Click Calculate Area.
Benefits
- Find area when you only have side lengths, not a height
- Check geometry homework
- Useful for land surveying and design
Frequently Asked Questions
It calculates a triangle's area purely from its three side lengths (a, b, c): first find the semi-perimeter s = (a+b+c)/2, then area = \u221a(s(s\u2212a)(s\u2212b)(s\u2212c)).
Any two sides of a triangle must add up to more than the third side (the triangle inequality) \u2014 if that's not true for your three numbers, no actual triangle can be formed.