Calculating Open Box Volume and Dimensions Algebra Word Problem

Published on July 11, 2026

Word-Problem

Solve for the volume of an open box created from a rectangular cardboard by cutting corners and folding. Determine the domain of the volume function and find dimensions for a specific volume.

Question

Answer

Based on the information provided in the problem, let’s solve it step by step.

Given Data:

  • Let the width of the original rectangular cardboard be cm.
  • The length of the cardboard is thrice the width, so length cm.
  • Squares of side cm are cut from each of the four corners.
  • The cardboard is then folded to form an open box.

Dimensions of the Open Box:

When the corners are cut and the sides are folded up:
  • The height ( ) of the box will be the side of the cut square: cm.
  • The width ( ) of the base will be the original width minus two cut-outs: cm.
  • The length ( ) of the base will be the original length minus two cut-outs: cm.

i. Find the volume of the open box and determine if the function is a polynomial.

The volume of a rectangular box is given by .
Conclusion: The resultant function is a polynomial function (specifically a quadratic polynomial) because it is an expression consisting of variables and coefficients, involving only the operations of addition, subtraction, multiplication, and non-negative integer exponents of variables.

ii. Find the possible domain for the volume function.

For the box to exist, all its physical dimensions must be positive:
  1. Height: (Always true).
  2. Width of base: .
  3. Length of base: .
To satisfy all conditions, must be greater than .
Domain: or cm.

iii. If the volume is , what dimensions of the box would be appropriate?

Set the volume function equal to :
Divide the entire equation by :
Using the quadratic formula :
Two possible values for :
  1. cm.
  2. cm (This is outside the domain ).
Using cm:
  • Height cm.
  • Width of box cm.
  • Length of box cm.
Appropriate dimensions: Height cm, Width cm, Length cm.