What tool is best suited for drawing a circle?

The compass is specifically designed for drawing circles, making it the most appropriate tool for this task. A compass consists of two arms: one arm holds a pointed end that acts as the pivot at the center of the circle, while the other arm holds a pencil or pen that traces the circular line as it rotates around the pivot. This mechanism allows for precise control of the circle's radius, ensuring an accurate and uniform shape.

In contrast, while a protractor is useful for measuring angles, it does not aid in circle creation. A ruler can draw straight lines effectively but cannot create a circular shape. Similarly, a square is designed for making right angles and straight edges, which makes it ill-suited for any circular drawing tasks. Therefore, the compass stands out as the ideal tool for this specific purpose.