Math
Triangle Calculator
Given three sides, compute area (Heron's), perimeter, all interior angles, height, and classify the triangle.
Inputs
Triangle Calculator
Result
Area
14.6969
- Perimeter
- 18
- Angle A
- 44.42°
- Angle B
- 57.12°
- Angle C
- 78.46°
- Height on a
- 5.8788
- Type
- Scalene · Acute
How it's calculated
Area = √(s(s−a)(s−b)(s−c)), s = (a+b+c)/2. cos A = (b²+c²−a²)/(2bc).
a=5, b=6, c=7 → area ≈ 14.697, angles ≈ 44.4°, 57.1°, 78.5°.
Common questions
What is Heron's formula?
It gives a triangle's area from its three side lengths without needing a height: A = √(s(s−a)(s−b)(s−c)).
How are the angles found?
The law of cosines solves for each angle given the three sides: cos(A) = (b² + c² − a²) / (2bc).
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