Law of Sines Calculator

a/sin(A) = b/sin(B) = c/sin(C). Solve any triangle given AAS / ASA / SSA.

Inputs

Result

Sides
b ≈ 12.267, c ≈ 11.305
C = 60.00° (180 − A − B).
  • Angle A50°
  • Side a10
  • Angle B70°
  • Angle C60.0000°
  • Side b12.266816
  • Side c11.305159
  • Common ratioa/sin A = 2R13.054073

Step-by-step

  1. C = 180° − A − B = 60.0000°.
  2. a / sin A = 10 / 0.7660 = 13.0541.
  3. b = ratio × sin B = 13.0541 × 0.9397 = 12.2668.
  4. c = ratio × sin C = 11.3052.

How to use this calculator

  • Enter angle A and its opposite side a.
  • Enter angle B.
  • Read computed angle C and remaining sides.

About this calculator

Law of sines: a/sin(A) = b/sin(B) = c/sin(C) = 2R (where R = circumradius). Use to solve triangles when you know two angles and one side (AAS or ASA): the third angle is 180° − A − B, then ratios give the missing sides. The SSA case ("ambiguous case") can have 0, 1, or 2 valid triangles depending on configuration.

Frequently asked

Best for AAS, ASA, or SSA triangles (one side + opposite angle, plus one more piece). For SAS or SSS, use law of cosines.

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