Triangle Solver Calculator

Solve any triangle using law of sines and cosines. Enter 3 known values (sides or angles) and calculate all missing measurements.

Input Values

Results

Case --
Area --
Perimeter --
Type --

Triangle Solving Methods

Law of Sines

  • Formula: a/sin(A) = b/sin(B) = c/sin(C)
  • Use when: You know 2 angles and 1 side (AAS, ASA)
  • Or: 2 sides and 1 non-included angle (SSA - ambiguous case)

Law of Cosines

  • c² = a² + b² - 2ab·cos(C)
  • Use when: You know 3 sides (SSS)
  • Or: 2 sides and included angle (SAS)

Triangle Cases

  • SSS: Three sides known
  • SAS: Two sides and included angle
  • ASA: Two angles and included side
  • AAS: Two angles and non-included side
  • SSA: Two sides and non-included angle (ambiguous)

Area Formulas

  • Heron's: √(s(s-a)(s-b)(s-c))
  • SAS: (1/2)ab·sin(C)
  • Base×Height: (1/2)bh