Ab is parallel to cd and ef is perpendicular to ab. the number of 90 degree angles formed by the intersections of ef and the two parallel lines ab and cd is

Barrett is comparing the membership fees for two museums. the art museum charges a one-time fee of $8.25 plus $2.25 per month. the science museum charges a one-time fee of $10.75 plus $3.50 per month. how much does barrett save by joining the art museum instead of the science museum?