Watch the video clip carefully.
To create the box, we need two sheets of papers.
The one of the dimensions of the first sheet was given in the diagram.
However, the dimension of the 2nd sheet was not given.
How would you describe the dimensions in the 2nd sheet (yellow) so that one can follow to draw the lines and construct the box easily?
Hint: You may introduce a variable x for one of the missing info in the 1st sheet (pink).