If there be no room below the line, the intersection may be taken above the line; that is to say, between the line and the given point.
Second Method, [Fig. 104]. From any two points B C at some distance apart, in the given line, and with the radii B A, C A, respectively, describe arcs cutting at A D. Draw the perpendicular A D.
Fig. 105.
Fig. 106.
Ex. 5.—To draw a parallel line through a given point, [Fig. 105]. With a radius equal to the given point C from the given line A B, describe the arc D from B, taken considerably distant from C. Draw the parallel through C to touch the arc D.
Second Method, [Fig. 106]. From A, the given point, describe the arc F D, cutting the given line at F; from F, with the same radius, describe the arc E A, and set off F D, equal to E A. Draw the parallel through the points A D.
Fig. 107.