Upon the issues being made up, or upon the lapse of time within which the parties served are required to appear by any summons issued as provided in the preceding section, the court shall empanel a jury to hear and determine the matters in issue, and if the jury shall find that the matters set forth in the petition are true and that any of the lands of the district have been benefited by the completed improvement, after offsetting any additional damages found to have been sustained by reason thereof, it shall determine and assess the benefits which have actually accrued, and shall specify in its verdict the respective amount of benefits per acre, if any, assessed to each particular tract of land, by legal subdivisions.