To create a datum plane at an angle to a face, what would you select?

To create a datum plane at an angle to a face, selecting a face along with a datum axis or a straight edge is the most effective approach. This method enables you to establish a reference plane that is not just parallel or perpendicular to the primary face but can also be oriented at a specific angle as dictated by the chosen datum axis or straight edge.

When you select a datum axis, you leverage its defined orientation to position the new datum plane precisely. This functionality is crucial in applications where angular relationships are significant, allowing for precise geometry creation that aligns with design requirements. Furthermore, the straight edge can define an angle relative to the face, effectively guiding the placement of the datum plane in relation to the existing geometry.

The other options either do not provide the necessary angular positioning or involve elements that do not guarantee the same level of precision or relevance to angular relationships. Thus, using a face in conjunction with a datum axis or straight edge is key to achieving the desired angled orientation for the datum plane.