Math

Free Law of Sines Calculator

Find a missing side or angle using the law of sines.

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Inputs

Result

Side b

10.7784

Side c12.2567
Angle C80.00°

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Short answer

Find a missing side or angle using the law of sines.

What is the Law of Sines Calculator?

Find a missing side or angle using the law of sines.

How does the Law of Sines Calculator work?

Enter the inputs above and read the result.

Formula

a/sin(A) = b/sin(B) = c/sin(C)

Variables

  • A,B,CTriangle's angles

Explanation

The ratio of a side to the sine of its opposite angle is constant across the triangle.

Examples

Applications

    Advantages

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        Common mistakes

          Tips

            Related concepts

            The Law of Sines Calculator sits inside the Math Calculators hub, in the geometry & shapes cluster. Length, area, volume and angle in two and three dimensions. Understanding the terms below makes the output easier to interpret and easier to compare against neighbouring measures.

            areaperimetervolumesurface areaanglecoordinate plane

            Practical use cases and industry applications

            Understanding Law of Sines

            Find a missing side or angle using the law of sines. Within math calculators, law of sines belongs to the geometry & shapes cluster, where it shares terminology and assumptions with closely related tools.

            Learning how law of sines is calculated

            The ratio of a side to the sine of its opposite angle is constant across the triangle. Working through the variables one at a time — A,B,C — makes the result reproducible by hand and easier to sanity-check.

            Using law of sines to make a decision

            Because outputs depend on the assumptions you enter, run more than one scenario before committing to a figure.

            How law of sines compares with related measures

            area, perimeter, volume, surface area all describe adjacent aspects of geometry & shapes. Comparing this calculator's output against those measures — using the related tools listed on this page — prevents a single metric from being read in isolation.

            Frequently asked questions

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