"resultant force="vec (OC)
vec(OC)=vec(OD)+vec(DC)
"resultant force="vec F
vec F=vec u+ vec l+vec k
u=10N
l=12*cos(60)=12*1/2=6 N
vec(OD)=u+l=10+6=16N
k=12*sin 60=12*sqrt 3/2=6 sqrt 3N
vec(DC)=k=6 sqrt 3 N
F=sqrt((OD)^2+(DC)^2)
F=sqrt(16^2+(6sqrt 3)^2)
F=sqrt(256+108)
F=sqrt(364)
F=19.08 N
tan beta=(DC)/(OD)
tan beta=(6sqrt 3)/16=0.64951905
beta=33 deg