Given a∥b , and c is not parallel to a or b, which statements must be true? Select each correct answer. m∠4=m∠8 the measure of angle 4 equals the measure of angle 8 m∠7=m∠10 the measure of angle 7 equals the measure of angle 10 m∠8=m∠9 the measure of angle 8 equals the measure of angle 9 m∠2=m∠7 the measure of angle 2 equals the measure of angle 7