Question

Question
For ΔABC
, find the measure of ∠C
to the nearest degree when side a=46
m, side b=30
m, and side c=20
m. (1 point)

Answer 1

Use the Law of Cosines: c^2 = a^2 + b^2 - 2ab cos C, so
cos C = (a^2 + b^2 - c^2) / (2ab) = (46^2 + 30^2 - 20^2) / (2·46·30) = 109/115 ≈ 0.947826.
C = arccos(109/115) ≈ 18.6°, which rounds to 19°.