For a folded-card activity, the net of a pyramid with a quadrilateral base shows the base area as 52 cm². The side triangles are labeled face 1: base 8 cm, height 6.5 cm; face 2: base 7 cm, height 4 cm; face 3: base 5 cm, height 9 cm; face 4: base 6 cm, height 7 cm. Which expression and value correctly represent the surface area?