At the annual township meeting or a special meeting, the electors of the township may approve expansion of the board of township supervisors from three to five members. At the first annual meeting after a special meeting at which the expansion is authorized, or at the annual meeting at which the expansion is authorized, the electors of the township shall elect three members of the board of township supervisors. Two of the members of the board elected under this section must be elected for three-year terms and one supervisor must be elected for a two-year term. Thereafter, terms of office of members of the board of township supervisors will be as provided in section 58-05-02.