5.8 The Law of Cosines Law of Cosines – Law of Cosines allows us to solve a triangle when the Law of Sines cannot be used. Most problems can be solved.

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5.8 The Law of Cosines

Law of Cosines – Law of Cosines allows us to solve a triangle when the Law of Sines cannot be used. Most problems can be solved in more than one way. Choosing the most efficient way to solve a problem is sometimes not obvious. Decision making is an important problem-solving strategy

Law of Cosines – Law of Cosines allows us to solve a triangle when the Law of Sines cannot be used. Most problems can be solved in more than one way. Choosing the most efficient way to solve a problem is sometimes not obvious. Decision making is an important problem-solving strategy

The Law of Cosines can be used to solve a triangle in the following cases Case 1. You know the measures of 2 sides and the included angle. Case 2. You know the measures of three sides.

Solve the triangle. Ex: A = 120, b = 9, c = 5

Solve the triangle Ex: a = 24, b = 40, c = 18

Find the area a = 4, b = 7, c = 9

Hero’s Formula

Find the Area a = 72, b = 83, c = 95