Thread: Law of Sines and Cosines

Solve triangle by either Law of Cosines or Law of Sines.

1. b = 7
c = 5
angle C = 150


2. c = 12
angle A = 140
angle C = 20


3. a = 22.3
b = 16.1
angle B = 100


4. A ship sails due west from a harbor for 22 nautical miles. It then sails 62 degrees south of west for another 15 miles. How far is the ship from the harbor?

(1) 5^2 = a^2 + 7^2 - 2(a)(7)cos150 , then find a .


(4) same thing , use cos rule to look for the distance