We can calculate the volume as the product of the area of the base and the height.
The area of the base is function of the square of the diameter, so we can write:
[tex]\begin{gathered} V=A_b\cdot h \\ V=\frac{\pi D^2}{4}\cdot h \\ V\approx\frac{3.14\cdot(20\operatorname{cm})^2}{4}\cdot4\operatorname{cm} \\ V\approx\frac{3.14\cdot400\operatorname{cm}\cdot4\operatorname{cm}}{4} \\ V\approx1256\operatorname{cm}^3 \end{gathered}[/tex]Answer: the volume of the box is 1256 cm^2.
