Frequently Asked Questions

What is the Law of Cosines?

The Law of Cosines is a formula relating the lengths of the sides of a triangle to the cosine of one of its angles. It states that: c² = a² + b² - 2ab × cos(C), where a, b, and c are the sides of the triangle and C is the angle opposite to side c.

When should I use the Law of Cosines?

Use the Law of Cosines when you have:

• Two sides and the included angle (SAS)
• Three sides (SSS)
• Any triangle where the Pythagorean theorem doesn't apply

What's the difference between Law of Cosines and Pythagorean theorem?

The Pythagorean theorem only works for right triangles, while the Law of Cosines works for any triangle. The Law of Cosines is actually a generalization of the Pythagorean theorem.

How accurate are the calculations?

Our calculator provides results accurate to several decimal places. For most practical applications, this level of precision is more than sufficient.

Can I use this calculator for homework?

Yes! Our calculator is a great tool for checking your work or understanding the steps involved in solving triangle problems. However, we recommend learning the concepts and practicing calculations by hand as well.

What do I do if I get an error message?

Common error messages occur when:

• The triangle inequality theorem is violated
• Negative values are entered for sides
• Angles are outside the valid range (0-180 degrees)

Check your inputs and make sure they form a valid triangle.

Does the calculator work in both degrees and radians?

Yes, our calculator can work with both degrees and radians. Make sure to select the correct unit of measurement before entering your values.