Question

A square with an area of 49 in2 is rotated to form a cylinder. What is the volume of the cylinder

Answer 1

343 pi in^3 ; exact volume 1078 in^3 ; Approximate volume Since it's not specified, I will assume the axis of rotation will be one edge of the square. With that in mind, here's the solution. Since the shape specified is a square with an area of 49 in^2, the length of any edge will be sqrt(49) = 7 inches. Since we're rotating along one edge, we will create a cylinder with a radius of 7 inches and a height of 7 inches. The volume will be the area of a circle with a 7 inch radius multiplied by the height of the cylinder. So V = pi*h*r^2 V = pi*7*7^2 V = pi*7*49 V = pi*343 V = 343pi V = 1077.56628; approximately. So the exact volume is 343pi in^3 and an approximate volume is 1078 in^3