The law of cosines tells us that 𝑎 = 𝑏 + 𝑐 − 2 𝑏 𝑐 ⋅ 𝐴. c o s. It may be useful to see that the law of cosines can be viewed as a generalized form of the Pythagorean theorem. In order to see this, let us consider an arbitrary triangle with an angle 𝐴 = 9 0 ∘. Inputting this value into the law of cosines, we can see ...Web