Question

Use the information to solve the triangle. Round your answers to two decimal places. Hint: draw a sketch first to determine if you should use Law of Sines or Cosines.

C=123°, a=41, b=57

Answer 1

c = 86.5 (3 sig. fig)

A = 23.4° (3 sig. fig.)

B = 33.6

Explanation:

Using cos Law,

c = √(57² + 41² - 2(57)(41)cos(123))

c = 86.5 (3 sig. fig)

Using sin Law,

sinA/41 = sin123/86.5

A = 23.4° or 157° (rejected) [C is 123°, if A is 157, it violates the angle sum of triangle]

Using angle sum of triangle,

B = 180 - 23.4 - 123 = 33.6