Answer:
C = 58.88 degrees
Step-by-step explanation:
We can use the law of cosines to find the missing angle measurement
c^2 = a^2 +b^2 -2ab cosC
Rearranging and solving for cos C
2ab Cos C = a^2 +b^2 - c^2
Divide by 2ab
cos(C) = a^2 + b^2 − c^2
------------------------
2ab
Substituting what we know a = 31 b = 21 c = 27
31^2 + 21^2 - 27^2
cos C = -----------------------------
2(31)(21)
cos C = .516897081
Take the inverse cos on each side
cos^-1 cos C = cos ^-1 (.516897081)
C = 58.88 degrees
