[PDF] 8 6 study guide and intervention the law of sines and law of cosines

What is the law of sines and cosines?

The Law of Sines and Law of Cosines The Law of Cosines Another relationship between the sides and angles of any triangle is called the Law of Cosines. You can use the Law of Cosines if you know three sides of a triangle or if you know two sides and the included angle of a triangle.

How do you prove the law of sines?

Generally, there are several ways to prove the Law of Sines and the Law of Cosines, but I will provide one of each here: Let ABC be a triangle with angles A, B, C and sides a, b, c, such that angle A subtends side a, etc. ... Theorem (Law of Cosines). c^2 = a^2 + b^2 - 2ab Cos [C]. Proof.

Can the law of sines help us solve triangles?

We have now solved triangles in the form of ASA, AAS, and if possible, SSA. That leaves us with the cases of SAS, and SSS. Here are two examples. Explain why the Law of Sines does not help us solve them.