Here's why:

* Lever: A lever is a rigid bar that pivots around a fixed point called a fulcrum. It amplifies force or changes the direction of force.

* Wheel and Axle: A wheel and axle system has a wheel attached to a central rod called an axle. When you apply force to the wheel, the axle rotates, and vice versa.

The Connection:

Think of the wheel as the lever arm, the axle as the fulcrum, and the force you apply to the wheel as the effort. The wheel and axle system uses the principle of leverage to multiply force or change the direction of movement. For example:

* Steering wheel: The steering wheel is the lever arm, the steering column is the axle, and your hands provide the effort.

* Bicycle wheel: The wheel is the lever arm, the axle is the fulcrum, and the pedals provide the effort.

Therefore, a wheel and axle is considered a special case of a lever where the fulcrum is at the center of the wheel, and the effort is applied to the rim of the wheel.