Law of Cosines & Heron's Formula

In this lesson, we will learn how to solve oblique triangles given SSS (side-side-side) or SAS (side-angle-side). We will begin our lesson with a simple derivation of the law of cosines. We will then show a step-by-step method for solving oblique triangles given SAS. Afterwards, we will move on to solving oblique triangles given SSS. We will then finish up our lesson by learning how to find the semiperimeter. We will use the semiperimeter along with Heron's formula to find the area of a triangle given SSS.