What is the surface are of a cereal box that is 12 inches and has a base of 3 inches and 8 inches

Question

The height is 12 inches tall and the base is 3 inches by 8 inches

Answer 1

The box, regardless of its contents, is a rectangular solid and it has six rectangular surfaces:

top & bottom congruent rectangles

front & back congruent rectangles

left & right side congruent rectangles.

 

each rectangle has an area that is the product of two dimensions, so total surface area is

2LW + 2LH + 2 HW.   

 

It is now time for you to compute, provided that you understand this method.