Question

Find C.
Round to the nearest tenth.
90 ft
55 ft
A
В
50 ft
C = [? ]°
YLaw of Cosines: c2 = a+ b2 - 2ab cos C

Answer 1

9514 1404 393

Answer:

  29.4°

Step-by-step explanation:

The equation can be rearranged to give C directly.

  C = arccos((a^2 +b^2 -c^2)/(2ab))

  C = arccos((90^2 +55^2 -50^2)/(2·90·55))

  C = arccos(8625/9900) ≈ 29.4002°

  C ≈ 29.4°