What is the surface area of the cuboidal box which is open at the top, if:
l= length of the cuboid,
b= breadth of the cuboid and
h= height of the cuboid
lb+2bh+2hl
When the cuboidal box is cut open, the total surface area is the sum of the areas of five rectangles as shown in the figure.
Surface Area =hl+lb+bh+hl+bh
⇒ Surface Area =lb+2bh+2hl