solve:

tan x/2= sqrt3/ 3

tan x/2 = √3/3

i recognize the 30-60-90 triangle, where
tan 30° = 1/√3 = √3/3

so x/2 = 30° or x/2 = 210° by CAST
x = 60° or x = 420°

or
in radians, x = π/3 or x = 7π/3