Answer:
The answer to your question is: 3600 cm ²
Step-by-step explanation:
Rectangular box:
length = 40 cm
breadth = 25
height = 20 cm
Area =
Area of the base = 40 x 25 = 1000 cm²
Area of the lateral sides = 2(40 x 20) = 1600 cm²
Area of the sides = 2(25 x 20) = 1000 cm²
Total area = 1000 + 1600 + 1000 = 3600 cm²
Well, the simplest form is

. Other fractions are

etc.
Do simplifications and amplifications to reach one from another.
THE ANSWER OF THIS QUESTION IS 9
900 all you have to do is add you add 450 +450 so you get 900 see easy