What is a primary use of the Helix feature in SolidWorks?

The Helix feature in SolidWorks is primarily used for generating spiral shapes. This feature allows you to create complex geometries that follow a helical path, useful for designing components such as springs, threads, and other curved profiles that require a continuous spiral form.

Using the Helix function, you can specify parameters such as the pitch, revolution, and direction of the spiral, enabling detailed control over the shape and dimensions of your design. This functionality is essential in various applications, from mechanical parts to artistic designs, where a spiral geometry is required.

The other options reflect different geometric creations that do not involve the spiral formation typical of the Helix feature. For example, creating straight lines or rectangular features pertains to basic two-dimensional shapes, while defining circular patterns involves the use of other features like the Circular Pattern tool rather than the Helix function. The focus on spiral shapes firmly identifies the correct option as the primary use of the Helix in SolidWorks.