Question

Define law of cosines

Answer 1

Hey mate!!

↪The Law of Cosines is used to find the remaining parts of an oblique (non-right)triangle when either the lengths of two sides and the measure of the included angle is known (SAS) or the lengths of the three sides (SSS) are known.  In either of these cases, it is impossible to use the Law of Sines because we cannot set up a solvable proportion.