A "regular quadrilateral" is a square, so the length and width are both 4 cm. The surface area of a rectangular prism is given by
S = 2(LW +H(L +W))
S = 2((4 cm)*(4 cm) +(6 cm)*(4 cm +4 cm))
S = 2(16 cm² +48 cm²)
S = 2*64 cm² = 128 cm²
The surface area of the prism is 128 cm².
