Final answer:
To measure a 60-degree angle, the Protractor head of a combination square should be used. A ruler is designed for measuring lengths in units like inches or millimeters, while a protractor measures angles.
Step-by-step explanation:
To measure a 60-degree angle with a combination square, you should use B) Protractor head. The protractor head is specifically designed to measure angles, and typically you would set the protractor to the desired angle and then check or draw this angle using the tool. For linear measurements, such as length or distance, a ruler would be the appropriate tool. The ruler can come with measurement units like inches, centimeters, or millimeters. In the context of physics problems, particularly those involving vectors, a ruler could be used to measure the magnitude of a resultant vector (R), whereas a protractor would be employed to measure the direction of R, by determining the angle it makes with a reference frame.