Answer:
Step-by-step explanation:
<C = ?
a = 22
b = 20
c = 18
Formula
c^2 = a^2 + b^2 - 2*a*b* cos(C)
Solution
18^2 = 22^2 + 20^2 - 2*22*20*cos(C)
324 = 484 + 400 - 880*cos(C)
324 = 884 - 880*Cos(C)
-560 = - 880 * cos(C)
-560 / - 880 = cos(C)
0.63636 = cos(C)
C = cos-1(0.63636)
C =50.48
