Which tool is used to mark parallel lines from a datum edge?

• A. Odd leg caliper
• B. Engineers mitre square
• C. Combination square
• D. Scriber

Answer: (A)

Marking lines that stay at a constant distance from a reference edge needs a tool that can ride along the edge while delivering a line offset by a set amount. The odd leg caliper fits this purpose because it has two legs at a right angle; you can place the short leg against the datum edge and use the other leg, with a marking tip, to scribe a line at a fixed offset. You can adjust the gap between the legs to set the exact distance, then sweep the tool along the edge to produce parallel lines consistently.

A scriber by itself will only make a single line and doesn’t maintain a fixed offset from the edge. An engineers mitre square is for establishing or checking right angles from a edge, not for laying out parallel lines. A combination square can mark lines or measure, but it isn’t inherently used to create multiple parallel lines at a set distance without extra setup.