Answer: piece of paper cut into a triangle
Explanation:
A plane surface lifted at an angle to horizontal from one edge is said to be an inclined plane. A wedge, a ramp or a screw are examples of a forms of inclined plane. A screw is like a inclined plane wound on a cylinder. These are simple machines. On the other hand, a piece of paper cut into a triangle is not an inclined plane as it does rise at an angle from horizontal. It is not a machine.