Symbols:
 Some of these symbols are used only in the strokes, others in legends, others in both.

 ≡ Coincident: indicates that two figures are coincident, occupying the same place in space;

 // Parallel: indicates that two figures are parallel to each other;

⊥  Perpendicular: it is placed at the intersection of two lines to emphasize that they are perpendicular;

/ Oblique: indicates that two figures are oblique to each other; 

 = Same: indicates that, within the same route, two measurements (distances or angles) are the same;

when it is necessary to indicate more equal measures, the signs - and ≡, among others, can be used.

Є Belongs: indicates that a figure belongs to another, that is, it is contained in it;