Projections With Numeral Marks. Projections of a Point and a Straight Line. Mutual Position of Straight Lines

Projections with numerical marks. Projection of a straight line is the relative position of straight lines. In projections with numerical marks, in order to determine whether these lines intersect or not, it is necessary to grade the lines, and if the lines have the same mark at the intersection point, then the lines intersect. If their marks are different at the point of intersection of the lines, then the lines are crossed. If the lines connecting the points with the same marks on the straight lines are parallel to each other, then the straight lines intersect, otherwise they intersect.