Law of Sines Calculator
Solve triangles using the Law of Sines when given angles and opposite sides
About this calculator
The Law of Sines Calculator helps you solve triangles by finding unknown angles and sides using the mathematical relationship a/sin(A) = b/sin(B) = c/sin(C). This powerful tool is essential for trigonometry students, engineers, surveyors, and anyone working with triangular measurements. Whether you're calculating distances in navigation, determining roof angles in construction, or solving geometry homework, this calculator provides accurate results when you know at least one angle-side pair and one additional measurement.
How to use
Enter the known values into the corresponding fields - you need at least two angles and one side, or two sides and one angle opposite to a known side. The calculator will automatically compute the missing measurements using the Law of Sines formula. Click calculate to get your results instantly.
Frequently asked questions
When can I use the Law of Sines?
Use it when you know two angles and any side (AAS/ASA) or two sides and an angle opposite one known side (SSA).
What is the ambiguous case in Law of Sines?
The SSA case can sometimes produce two valid triangles, known as the ambiguous case, when the given angle is acute.
Can this solve right triangles?
Yes, but basic trigonometric ratios (sin, cos, tan) are often more direct for right triangles than the Law of Sines.