Triangle & Trigonometry Calculator
Solve Unknown Sides, Angles & GeometryEnter any 3 values (at least one must be a side length):
Triangle Geometry Output
Scalene Acute Triangle
Area: 14.70 u²
Perimeter: 18.00 u
Sides (a, b, c):5.00, 6.00, 7.00
Angles (A, B, C):44.42°, 57.12°, 78.46°
Semi-Perimeter (s):9.00
Inradius (r):1.63
Circumradius (R):3.57
Frequently Asked Questions
• Law of Sines:
• Law of Cosines:
a / sin(A) = b / sin(B) = c / sin(C) = 2R (where R is circumradius).• Law of Cosines:
c² = a² + b² − 2ab × cos(C). Useful when you know all three sides (SSS) or two sides and the included angle (SAS).
Given sides a, b, c with semi-perimeter
s = (a + b + c) / 2:Area = √[s(s − a)(s − b)(s − c)].