`tan theta+tan 2 theta+sqrt(3) tan theta tan 2 theta=sqrt(3)`
or `tan theta+tan 2 theta=sqrt(3) (1- tan theta tan 2 theta)`
or `(tan theta+tan 2 theta)/(1- tan theta tan 2 theta)= sqrt(3)`
or `tan 3 theta=sqrt(3)="tan" pi/3`
`rArr 3 theta=n pi +pi/3, n in Z`
or `theta=(n pi)/3+pi/9, n in Z`
