1. EXAMPLE: Determine the length of CB. 58 o 32 m 40 m A B C 58 o b = 32 m c = 40 m A B C a = ? CB is about 36 meters long.

2. The posts of a hockey net are 1.8 m apart. A player tries to score a goal by shooting the puck along the ice from a point that is 4.3 m from one goalpost and 4.0 m from the other goalpost. Determine the measure of the angle that the puck makes with both goal posts. b = 4.3 m c = 1.8 m A B C = ? a = 4.0 m We will use this version of cosine law:

3. b = 4.3 m c = 1.8 m A B C = ? a = 4.0 m Therefore, Angle C is about 25 o.