Triangle Calculator
Calculate area, perimeter, all angles and sides for any triangle. Supports SSS, SAS, and more.
Triangle Type
Area
6.0000 sq units
Perimeter
12.0000 units
Triangle Type
Scalene
Angles
Angle A
36.87°
Angle B
53.13°
Angle C
90.00°
About Triangles
Triangle inequality rule
For any valid triangle, the sum of any two sides must be greater than the third side. If A + B > C, B + C > A, and A + C > B, a valid triangle can be formed.
Types of triangles
Equilateral: all 3 sides equal, all angles = 60°
Isosceles: 2 sides equal, 2 base angles equal
Scalene: all sides different, all angles different
Right: one angle = 90°, satisfies Pythagorean theorem
Area formulas
SSS (Heron's): Area = √(s(s-a)(s-b)(s-c)) where s = semi-perimeter
SAS: Area = ½ × a × b × sin(C)
Base-height: Area = ½ × base × height
🔒 All calculations happen in your browser — no data is sent to any server. Results are for informational purposes only.