Using law of cosines to find our missing length of a triangle

The video tutorial explains how to solve a triangle problem using the law of cosines. It begins by introducing the problem and the given values of the triangle. The instructor then discusses the decision-making process between using the law of sines or cosines, ultimately choosing the latter due to the available information. The tutorial proceeds with a step-by-step application of the law of cosines, including detailed calculations, to find the length of side a. The video concludes with the final result of the calculation.

What is the value of B^2 when B is 12.4?

What is the final calculated value of side a?