Verified answer

solve 2sin²θ-sinθ = 0

or sinx(2sinx-1)=0(here x=theta)

or sinx=0 or 2sinx-1=0

or sinx=sin0=sin180=sin 360

so x=0,180,360

and 2sinx-1=0

or sinx=1/2

or sinx=sin30

so ,x=30

so answer , x=0,30,180,360

By inspection th=0 and 180.