Use the law of sines to find the measure of angle C.

C = 43.6 degrees (1 dp)

You cannot find C using the sine law without knowing one of the other angles.
In your previous question I showed you that A = 71.5
sin(C)/16 = sin(71.5...)/22
sin(C) = 16 x sin(71.5...)/22 = 0.68977...
C = sin^-1(0.68969) = 43.6 degrees