A petition under this subtitle shall allege that a child who is required to attend school failed to attend school without lawful excuse and shall set forth in clear and simple language the facts supporting the allegation. Whenever a petition is filed under this subtitle the court shall hold an adjudicatory hearing. The rules of evidence under Title 5 of the Maryland Rules shall apply at an adjudicatory hearing under this section. The allegations in a petition under this subtitle shall be proved by a preponderance of the evidence.