Tan20 degree + tan40 degree + root 3 tan20 degree, tan40 degree =?

Tan20 degree + tan40 degree + root 3 tan20 degree, tan40 degree =?

Tan 20 degree + Tan 40 degree + root 3 Tan 20 degree Tan 40 degree
=Tan60 * (1-tan20 tan40) + root 3 tan20 degree tan40 degree
=√ 3 * (1-tan20 tan40) + √ 3tan20 degree tan40 degree
=√3