Page:An introduction to linear drawing.djvu/27

6 ﻿26. Draw a rectangular, or right angled triangle, (figs. 12 and 13.)

This is a triangle of which one of the angles is a right angle, as the lower left hand one in fig. 12, and the top one in fig. 13. The base may be horizontal or inclined.

27. Make a rectangular isoceles triangle.

There is no difference between this and figures 12 and 13, except that in an isoceles triangle, two of the sides must be of equal length. In fact, fig. 12 is an isoceles.



Figure 13, though rectangular, is a scalene also.

28. Draw a rectangle. (fig. 14.)

A rectangle is properly a figure with four sides, of which each two opposite sides are equal and parallel, and of which all the angles are right angles.



The lower side is the base, and the right or left side is the height.

To ascertain its correctness, the Monitor may examine every angle with his quadrant of pasteboard, or he may with his dividers see if the left hand upper, and