Cosine Law
Solving triangles with SAS/SSS and choosing the right law.
Overview Cosine Law — Grade 11 Trigonometry Beyond Right Triangles Unit Overview
In this Grade 11 Canadian mathematics unit, learners extend triangle solving beyond right triangles by using the Cosine Law in side-angle-side (SAS) and side-side-side (SSS) situations. By the end of the unit, they can choose when the Cosine Law is the correct tool, solve for unknown sides or angles in any triangle when enough information is given, and decide when another method such as the Sine Law or right-triangle trigonometry is more efficient.