Since a rectangle is rolled along length then circumference of circle is equal to length of rectangle and breadth equals to height.
=) 2*pi*r = 42cm
=) 2*22/7 * r = 42cm
=) r = 42*7 / 2*22
=) r = 147/22 cm
Since Volume of cylinder = pi* r^2*h
= 22/7 * 147/22 * 147/22 * 16 cm^3
= 2245.09 cm^3.