To have rules and order

"做事要有規有矩" is an idiom in Chinese that means one should act in an orderly and methodical manner.

In ancient China, "規" (guī) refers to a compass or a pair of compasses used for drawing circles, while "矩" (jǔ) refers to a set square or a carpenter's square composed of two rulers of different lengths intersecting at a right angle and marked with scales.

The use of compasses and set squares was not only limited to drawing but also extended to measurement. In historical texts, we find references to their significance in various contexts. For example:

In the "Records of the Grand Historian" (《史記》), it is mentioned that during the flood control efforts of Yu the Great, he used the "left measuring cord and right compass" (左准繩、右規矩).

In the book "Mozi" (《墨子》), it is recorded that "wheelwrights use the Mo compass and square to measure the squareness and roundness of the world" (輪匠執莫規矩，以度天下之方圓).

In the book "Mencius" (《孟子》), it is mentioned that "without compasses and set squares, one cannot achieve squareness and roundness" (無規矩不能成方圓).

These references highlight the importance of compasses and set squares in practical applications, including drawing, measurements, and achieving precision in various endeavors.