Answer:
The surface area of door is 33 680 cm².
Step-by-step explanation:
Given that the surface area of a cuboid which is the 3D of rectangle is :
[tex]s.a = 2(l \times w) + 2(l \times h) + 2(w \times h)[/tex]
[tex]let \: l = 80 \\ let \: w = 3 \\ let \: h = 200[/tex]
[tex]s.a = 2(80 \times 3) + 2(80 \times 200) + 2(3 \times 200)[/tex]
[tex]s.a = 2(240) + 2(16000) + 2(600)[/tex]
[tex]s.a = 480 + 32000 + 1200[/tex]
[tex]s.a = 33680 \: {cm}^{2} [/tex]
