What action should be taken to unlock from a sketch plane?

Unlocking from a sketch plane in Solid Edge is accomplished by clicking the lock icon located in the upper right corner of the interface. This action is designed to provide a simple and intuitive way to control the constraints applied to a sketch. The lock icon symbolizes the current state of the sketch—locked or unlocked. When you click on it, you effectively toggle the locking mechanism, thereby allowing you to modify the sketch freely without the constraints imposed by the locked state.

This method is particularly user-friendly because it visually conveys the status of the sketch and provides immediate feedback on whether the sketch is locked or unlocked. Therefore, accessing this feature through the lock icon streamlines the workflow for designers, making it easier to manage their sketches without needing to navigate through multiple menus or options.

Other methods, while they may seem plausible, require additional steps or may not be as direct, which can slow down the design process. Utilizing the lock icon is the most efficient way to manage the locking state of a sketch plane.