Important formulas in this chapter

For the standard form of inverse kinematics, you use the law of cosines formula.

Law of cosines:

a2 = b2 + c2 − 2 * b * c * cos A
 b2 = a2 + c2 − 2 * a * c * cos B
 c2 = a2 + b2 − 2 * a * b * cos C