Wash. Rev. Code § 35.58.130
At the first meeting of the metropolitan council following the formation of a metropolitan municipal corporation, the mayor of the central city shall serve as temporary chair. As its first official act the council shall elect a chair. The chair shall be a voting member of the council and shall preside at all meetings. In the event of his or her absence or inability to act the council shall select one of its members to act as chair pro tempore. A majority of all members of the council shall constitute a quorum for the transaction of business. A smaller number of councilmembers than a quorum may adjourn from time to time and may compel the attendance of absent members in such manner and under such penalties as the council may provide. The council shall determine its own rules and order of business, shall provide by resolution for the manner and time of holding all regular and special meetings and shall keep a journal of its proceedings which shall be a public record. Every legislative act of the council of a general or permanent nature shall be by resolution.
RCW 35.58.130