Sammy is classifying quadrilateral EFGH. How can she use coordinate geometry to determine whether EFGH is a parallelogram? E(0, 4), F(0, 7), G(1, 5), H(1, 2) Sammy can use the distance formula to show that the opposite sides have equal slopes. Sammy can use the distance formula to show that all sides are equal. Sammy can use the slope formula to show that the opposite sides have equal slopes. Sammy can use the slope formula to show that all sides are equal.