Find the volume of the cylinder whose height is 7 and the circumference of the base is 4.

 We know that the volume of the cylinder
is:

 V = r^2 * pi * h where r is the radius and h is the
height.

Given that the height is h =
7

==> V = r^2 * pi * 7

Now to
determine the radius ( r), we will use the circumference formula.

We
know that the circumference of a circle is given by the formula:

C =
2* pi * r

Given C = 4.

==> 2* pi
*r = 4.

==> r= 4/2pi =
2/pi.

==> r= 2/pi.

==> V
= ( 2/pi)^2 * pi * 7.

==> V = 4/pi * 7 =
28/p.i

Then, the volume of the cylinder is 28/pi cubic
units.