Squares see common use in woodworking, metalworking, construction and technical drawing.
[1] Some squares incorporate a scale for measuring distances (a ruler) or for calculating angles.
A bright light or feeler gauges can be used to check for gaps between the square and the object being referenced.
[35] Historically squares have also been used by woodworkers, such as joiners and carpenters, as symbols in signs and heraldry to represent their trade.
[36] The square as a symbol is also seen in artistic representations of the Christian saints Thomas the Apostle and James the Less.