Triangle Calculator
Calculate triangle properties from three sides: area, perimeter, angles, and classification.
How to Use This Calculator
Enter your values in the fields above and click "Calculate" to get instant results. This triangle calculator provides accurate results with step-by-step explanations.
Formula
Area = √(s(s-a)(s-b)(s-c)) where s = (a+b+c)/2 (Heron's formula)
Quick Examples
- Sides 5,6,7 → Area ≈ 14.70, Scalene Acute
- Sides 3,4,5 → Area = 6, Right
Frequently Asked Questions
What is Heron's formula?
Heron's formula calculates triangle area from three sides: A = √(s(s-a)(s-b)(s-c)), where s is the semi-perimeter (a+b+c)/2.
How do I find the angles of a triangle from its sides?
Use the law of cosines: cos(A) = (b²+c²-a²)/(2bc), then take the inverse cosine.