From any point D in the given line with the radius D C, describe the arc C E, and from C with the same radius describe the arc D F. Take E C, and set it off from D to F. Through C, and F draw C F for the parallel required. [Fig. 3].
To divide an angle into two equal parts.
From B as a centre with any radius describe an arc A C. From A, and C with any radius describe arcs intersecting each other in D. Then draw B D, and it will bisect the angle. [Fig. 4.]
PRACTICAL GEOMETRY.
Fig. 1-9.
Fig. 10-14.
To divide a right angle into three equal parts.