Between two inclined lines to draw a circular arc to fill up the angle (Fig. 33).

Let A B and D E be the inclined lines. Bisect the inclination by the line F C, and draw the perpendicular A F D to define the limit within which the circle is to be drawn. Bisect the angles A and D by lines cutting at C, and from C, with radius C F, draw the arc H F G, which will be the arc required.