We have already mentioned that with Autocad we can make drawings of very different types, from architectural plans of a whole building, to drawings of machinery pieces as fine as those of a clock. This imposes the problem of the units of measurement that one drawing or the other requires. While a map can have as units of measure meters, or kilometers depending on the case, a small piece can be of millimeters, even of tenths of a millimeter. In turn, we all know that there are different types of units of measurement, such as centimeters and inches. On the other hand, the inches can be reflected in decimal format, for example, 3.5 "although it can also be seen in fractional format, such as 3 ½". The angles, on the other hand, can be reflected as decimal angles (25.5 °), or in degrees minutes and seconds (25 ° 30 ').
All this forces us to consider some conventions that allow us to work with the units of measurement and the appropriate formats for each drawing. In the next chapter we will see how to choose the formats of the units of measure and their precision. Consider for the moment how the problem of the measures itself in Autocad is raised.