Gio is studying the rectangular pyramid below. A rectangular pyramid. The rectangular base has a length of 9.6 millimeters and width of 4.2 millimeters. 2 triangular sides have a base of 9.6 millimeters and height of 4.8 millimeters. 2 triangular sides have a base of 4.2 millimeters and height of 6.5 millimeters. He believes the surface area, in square millimeters, can be found by simplifying this expression. (4.2) (9.6) + one-half (4.2) (6.5) + one-half (9.6) (4.8) What error is Gio making? He used the wrong values as the bases of the lateral faces. He used the wrong expression to represent the area of the base of the pyramid. He used two different values as the heights of the lateral faces. He used an expression for surface area that did not include all the faces.