Frank Vashaw, a history teacher and baseball coach at North Gwinnett High School, has resigned, citing personal reasons, school system officials said Wednesday. Questions had been raised about Vashaw’s role in the possible inappropriate use of school facilities, the details of which were not disclosed. Vashaw, it was alleged, did not follow the district’s process for use of school facilities by outside groups. Vashaw, according to a statement from the district, resigned before a human resources’ investigation. As a result, information will be forwarded to the Professional Standards Commission, the state agency that licenses teachers. Vashaw joined the school district in 2005.