The Arc tool in Figma lets you manipulate curved shapes and is useful for creating pie charts, progress bars, custom loader animations, or simply adding a unique curved element to your design.

To use it, first draw a circle or an ellipse using the Ellipse tool. Once drawn, hover over the shape, and you'll see a handle appear on its right-hand side, starting at the point marked as 0. This handle controls the arc. To create an arc, click and drag this handle around the circle. The distance you drag the handle determines the extent of the arc. You can create anything from a small curve to a semi-circle, or even a near-complete circle.

Once you do this, two more handles will appear. Using the start handle (which has a dot inside it), you can decide where the arc begins, and using the ratio handle, you can change the circle to a ring.