Question 3 of 5. What is the theoretical exact reference from which other measurements are made? Datum Axis of the Datum Target Datum Plane Mark for follow up Question 4 of 5. How is the term "Datum Target" described? Referenced measuring point based on the diameter or center of a hole Referenced measuring point based on an edge or surface o Location on a part where the measuring tools would physically touch Designated point, line, or area that is used in establishing a datum Mark for follow up Question 5 of 5. What is the actual location on a part where the measuring tools would physically touch? Datum Point Datum Axis Datum Target Datum feature Mark for follow up