Ohio Rev. Code § 709.15: Petition to board of county commissioners.

The application of a municipal corporation to the board of county commissioners requesting the annexation of contiguous territory under section 709.16 of the Revised Code shall be by a petition setting forth that, under an ordinance of the legislative authority of the municipal corporation, the territory described in the petition was authorized to be annexed to the municipal corporation. The petition shall contain an accurate legal description of the perimeter and shall be accompanied by an accurate map or plat of the territory proposed for annexation.