Answer:
Surface area of the sheet: 296 square meters
Area of tank: 480 cubic meters
Explanation:
Don't forget your units!
"determine the iron sheet required for the fabrication" is asking for the surface area of the rectangular prism.
This is found by adding the five sides of the prism. The top side is excluded because it is open.
Front and back: 2(12m * 5m) = 120m^2
Left and right: 2(8m * 5m) = 80m^2
Floor: (12m * 8m) = 96m^2
120m^2 + 80m^2 + 96m^2 = 296m^2
The volume is found using standard methods. The open top does not have an impact here.
12m * 8m * 5m = 480m^3