A rectangular box is in the shape of cuboid.
Volume of cuboid = Length x Breadth x Height.
It is given that the dimension of the mail box are
[tex]4\frac{1}{2}feet\text{ by }2\text{ f}eet\text{ by 2}\frac{1}{2}feet[/tex]
i.e.
[tex]\begin{gathered} \text{Length}=4\frac{1}{2} \\ \text{Breadth}=2 \\ \text{Height}=2\frac{1}{2} \end{gathered}[/tex]
Substitute the value in the expression of volume.
[tex]\begin{gathered} \text{Volume of mail box=Length}\times Height\text{ }\times\text{Breadth} \\ \text{Volume of mail box=4}\frac{1}{2}\times2\frac{1}{2}\times2 \\ \text{Volume of mail box=}\frac{9}{2}\times\frac{5}{2}\times2 \\ \text{Volume of mail box=}\frac{90}{4} \\ \text{Volume of mail box=22.5 f}eet^3 \end{gathered}[/tex]
Answer: The volume of mail box is 22.5 feet³