Tolong ya pake caranya thanks

dik : a= (1,1,0)
b= (0,1,0)

cos < (a,b) = a.b / |a| |b|
= 1.0+1.1+1.0 /(√1^2+1^2+0 )(√0+1^2+0)
= 1 / √2
jadi <(a,b) = 60°