Question

Which plane figure generates a cylinder when it rotates about the dashed line?

Answer 1

The circle will form a sphere. (See 1st figure attached)

The rhombus (it can also be a square) will form a 2 cones attached at the bottom. (See 2nd figure attached)

The rectangle will form a cylinder. (See 3rd figure attached)

The triangle will form a cone.


Answer: The third figure.