Set square

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In American English, a set square is an alternative name for a T-square.
triangle, set square

A set square or triangle (American English) is an object used in engineering and technical drawing, with the aim of providing a straightedge at a right angle or other particular planar angle to a baseline.

The most simple form of set square is a triangular piece of transparent plastic (or formerly of polished wood) with the centre removed. More commonly the set square bears the markings of a ruler and a half circle protractor. The outer edges are typically bevelled. These set squares come in two usual forms, both right triangles: one with 90-45-45 degree angles, the other with 30-60-90 degree angles. Combining the two forms by placing the hypotenuses together will also yield 15° and 75° angles. They are often purchased in packs with protractors and compasses.

Less commonly found is the adjustable set square. Here, the body of the object is cut in half and rejoined with a hinge marked with angles. Adjustment to the marked angle will produce any desired angle up to a maximum of 180°.

The square is used in the Square and Compasses, the emblem of the Freemasons.[1] It is also depicted on the Installed Master apron of a Freemason.

The square and compasses, emblem of the Freemasons
Installed Master Freemason apron

References[edit]

  1. ^ http://www.masons.org.au/

See also[edit]