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What is the Triangle Calculator?

The Triangle Calculator calculates the area of a triangle using the lengths of its three sides (Heron's Formula).

How to Use This Calculator

1

Enter the lengths of all three sides (a, b, and c).

2

Click 'Calculate' to see the Area.

Example Calculation

Sides 3, 4, 5

Semi-perimeter (s) = (3+4+5)/2 = 6. Area = √(6 * (6-3) * (6-4) * (6-5)) = √(6*3*2*1) = √36 = 6.

Frequently Asked Questions

Pro Tips

  • Check the triangle inequality theorem if you are unsure about the side lengths.
  • This calculator works for scalene, isosceles, and equilateral triangles.