Question

What 2D shape could have been rotated about one of its sides to form a cylinder

Answer 1

Answer:

A rectangle

Step-by-step explanation:

If you were to take a rectangle a put it on to a 3 dimensional coordinate plane, you can put one entire side against an axis (lets use the y axis for example). Take the long side of a rectangle, rotate it along the y axis, and you get a 3 dimensional cylinder.