It should be that you can't draw squares and circles without compasses and rulers. This is what our math teacher said in class.

"No rules, no Fiona Fang" is a common saying, which often emphasizes that everything must have certain rules, rules and practices, otherwise it will not succeed. It originally came from the carpenter's term, and "gauge" refers to compass. When carpenters work, they will encounter the work of making round windows, doors, round tables and stools. , and ancient craftsmen already know to draw a circle with "rules"; "Moment" is also a woodworking tool, which refers to a curved ruler. The so-called bending ruler is not a bending ruler, but a right-angled ruler. It is a necessary ruler for carpenters to make square doors, windows, tables and stools.