Respuesta :

I think it's D. But I'm not sure if my math was correct
Using sin law;

sin A/ a = sinB/ b

where A = C or 90 degrees; a = 21
B = ? , b = 8

solving for b;
sin(90) / 21 = sin(B) / 8 ; B = 22.39 degrees

Total angle of triangle = 180

180 - 90 - 22.39 = x
x = 67.607 degrees