Respuesta :

321 because you need to use the formula

Answer:

[tex]9600 \: {ft}^{2} \\ [/tex]

Step-by-step explanation:

Area of front rectangle -

= 2 ( length × breadth )

= 2 ( 40 × 30 )

= 2 ( 1200)

[tex] = {2400 \: ft}^{2} \\ [/tex]

Area of other rectangles -

= 4 ( length × breadth )

= 4 ( 60 × 30 )

= 4 ( 1800)

[tex] = 7200 \: {ft}^{2} \\ [/tex]

Surface area of the rectangular prism

[tex] = {2400 \: ft}^{2} + {7200 \: ft}^{2} \\ = {9600 \: ft}^{2} \\ [/tex]