Trigonometry Triangle Solver

Law of Sines — Triangle Solver

Solve oblique (non-right) triangles using a/sinA = b/sinB = c/sinC. Supports AAS, ASA, and SSA (ambiguous case — may yield 0, 1, or 2 triangles). Labeled diagram included.

AAS, ASA, SSA cases
Ambiguous case detection
Labeled triangle diagram
Live
Inputs
Case
Quick examples
Solution
Select a case, enter 3 known values, and press Solve Triangle.
Angles
A
B
C
Sides
a
b
c
Area = ½bc·sinA
Triangle 2 (second solution for SSA ambiguous case):
B₂
C₂
c₂
Step-by-Step Solution
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Triangle Diagram
Law of Sines
a/sinA = b/sinB = c/sinC

The Law of Sines relates each side to the sine of its opposite angle. AAS/ASA: two angles determine the third (A+B+C=180°), then use the ratio to find sides. SSA (ambiguous case): given a, b, A — compute sinB = b·sinA/a. If sinB > 1: no triangle; sinB = 1: one right triangle; sinB < 1: possibly two triangles (B and 180°−B).

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