To find the volume of a cylinder, just follow this simple formula:
pi * r^2 * h = V
So, first find the radius of the base (take the diameter of the circle and literally divide it by 2), and then square the radius. From there, multiply the radius by pi (3.141 should be ok if your teacher didn’t specify what they wanted) and then multiply that product by the HEIGHT of the cylinder. And you found your volume!