Having a little problem solving this problem and need to find the best formula to do this problem.
A manufacturer is designing special packaging for a product in the shape of a truncated pyramid. A truncated pyramid is a pyramid with the top cut off. The model he is building is included. The bases are not regular figures. The lateral sides are trapezoids. The height of each trapezoid face is 12 cm. Determine the amount of material needed to build the model (assume no overlap on the side).With the measurements of the bottom of the trapezoids are 8cm,10cm and the top 3cm, 4cm.

Question

Having a little problem solving this problem and need to find the best formula to do this problem.
A manufacturer is designing special packaging for a product in the shape of a truncated pyramid. A truncated pyramid is a pyramid with the top cut off. The model  he is building is included. The bases are not regular figures. The lateral sides are trapezoids. The height of each trapezoid face is 12 cm. Determine the amount of material needed to build the model (assume no overlap on the side).With the measurements of the bottom of the trapezoids are 8cm,10cm and the top 3cm, 4cm.