Page:An introduction to linear drawing.djvu/33

12 ﻿10.Draw a polygon, and from a central point draw diagonals, then draw a parallel polygon within and outside of the first drawn.(fig. 8.)

11.Make a triangular pyramid.(fig. 9.)

First draw the triangle which forms the base, then place a dot for the point or apex, and draw right lines from the point to each angle of the base.

12.Draw a quadrangular (or four angled) pyramid.(fig. 10.) then cut it by a plane parallel to its base.

The process is the same as in the preceding figure. The plane, or parallel to the base, must be the last thing done. The height of the pyramid is a perpendicular dropped from the apex or summit to the base. The pupil must be careful to distinguish the front lines from the back lines of the figure.

13.Make a six sided pyramid.(fig. 11.)

14.Make a five sided pyramid.(fig. 12.)

15.Make a five sided pyramid, and cut it by a plane parallel to the base.(fig. 12.)