The formula of the surface area of the rectangular prism is equal: [tex]A=2(wl+wh+lh)[/tex] where: l - length w - width h - height We have: l = 5m w = 8m h = 9m Substitute: [tex]A=2\cdot(5\cdot8+5\cdot9+8\cdot9)=2\cdot(40+45+72)=2\cdot157=314\ m^2[/tex]