Math CentralQuandaries & Queries


Question from Brooklyn, a student:

What is the equation to find the length of the third side of a triangle if you have the length of A, B, and the angles(s)?

Hi Brooklyn.

It is called the Law of Cosines and it is described on this page or the Law of Sines described on this page.

If you have a right-angled triangle, you might find it easier to work with the Pythagorean Theorem, described here.

Hope this helps,
Stephen La Rocque.

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