Description:
This lesson will help students understand the law of cosines and the Pythagorean theorem. The material has students find out whether a triangle is acute, obtuse, or right; determine a formula for the law of cosines to relate the sides of any type of triangle, and explain how the Law of Cosines is an extension of the Pythagorean theorem. Student activity sheets are included. This material is intended for grades 9-12 and should require 2 class periods to complete.

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