To calculate the volume of a cylinder you have to multiply the area of the circle by the height of the cylinder.
[tex]\begin{gathered} V=A\cdot h \\ V=\pi r^2\cdot h \end{gathered}[/tex]We know that the radius of the circle is r=4 and the height of the cylinder is h=7, replace both values on the formula to determine the volume:
[tex]\begin{gathered} V=\pi(4^2)\cdot7 \\ V=\pi\cdot16\cdot7 \\ V=112\pi \\ V\approx351.86 \end{gathered}[/tex]The volume of the cylinder is approximately 351.86 cubic units.