A Ruler

TITLE: Ruler

PURPOSE:To explain how something works or how something occurs

DEFINITION: A Ruler is for school

Rulers have long been made from different materials and in a wide range of sizes. Some are wooden.

Plastics have also been used since they were invented; they can be modelled with length markings instead of being scribed.

Metal is used for more durable rulers for use in the workshop; sometimes a metal edge is embedded into a wooden desk ruler to preserve the edge when used for straight-line cutting

A ruler can be 12 inches or 30 cm in length. It is useful for a ruler to be kept on a desk to help in drawing.

Shorter rulers are convenient for keeping in a pocket.Longer rulers, e.g., 18 inches (45 cm) are necessary in some cases.

Rigid wooden or plastic yardsticks, 1 yard long, and meter sticks, 1 meter long, are also used. Classically, long measuring rods were used for larger projects, now superseded by tape measure or laser rangefinders.