Forgot your password?

Content on this page requires a newer version of Adobe Flash Player.

Get Adobe Flash player

A ruler, sometimes called a rule or line gauge, is an instrument used in geometry, technical drawing, printing  and engineering/building to measure distances and/or to rule straight lines.Rulers made from Ivory were in use by the Indus Valley Civilization period prior to 1500 BC. Excavations at Lothal (2400 BC) have yielded one such ruler calibrated to about 1/16 in (1.6 mm).