(a) Trial by jury. Cases required to be tried by jury shall be so tried unless the defendant waives a jury trial with the approval of the court. The waiver shall be either by written consent filed in court or by oral consent in open court entered on the record.(b) Jury of less than twelve. Juries shall be of 12 but at any time before verdict the parties may stipulate in writing with the approval of the court that the jury shall consist of any number less than 12.(c) Trial without a jury. In a case tried without a jury the court shall make a general finding and shall in addition, on request made at the time of the general finding, find such facts specially as are requested by the parties. Such special findings may be orally in open court or in writing at any time prior to sentence.