Law Of Sines Calculator
Solve triangles using the Law of Sines. Enter two angles and one side, or two sides and one angle, and calculate the missing sides and angles.
Published by:
isCalculator Editorial Team
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How to use this tool?
To use the Law of Sines Calculator, follow these steps:
- Enter known values: Input angles in degrees and sides in any consistent unit (e.g., all in meters or all in feet). At least one side and two other values (angles or sides) are required.
- Click "Calculate": The calculator will compute missing angles (using the 180° triangle sum) and sides using the Law of Sines: a/sin(A) = b/sin(B) = c/sin(C).
- Review results: The output shows all three angles (to 2 decimals) and sides (to 4 decimals), along with a step-by-step explanation.
- Check for errors: If inputs are invalid (e.g., angle sum > 180°, missing side), an error message will appear. Correct the highlighted fields and try again.
Note: The calculator does not handle the ambiguous case (SSA) fully; ensure your inputs form a valid triangle.
Previous Results
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Frequently Asked Questions
The Law of Sines states that the ratio of a side length to the sine of its opposite angle is constant for all three sides of a triangle.
You need at least one side and two other values (angles or sides). Typically, two angles and one side (AAS or ASA) or two sides and one angle (SSA).
Yes, the Law of Sines works for any triangle, not just right triangles. However, the SSA case may have ambiguous solutions.
