We'll use the Law of Cosines We'll call side a = length 5 side b = length 8 side c = length 10 and their corresponding angles as A, B and C "C" would be the largest angle cos (C) = (a^2 + b^2 - c^2) / 2 * a * b cos (C) = (5^2 + 8^2 - 10^2) / 2 * 5 * 8 cos (C) = 25 + 64 -100 / 80 cos (C) = -11 / 80 cos (C) =
-0.1375
arc cosine (
-0.1375
) = 97.903 Degrees The largest angle is 97.903 Degrees
