[ CXXXIX]
Steps in Angular Perspective
First draw the base ABCD (Fig. 251) at the required angle by the new method (Fig. 250). Produce BC to the horizon, and thus find vanishing point V. At this point raise vertical VV·. Construct
first step AB, refer its height at B to line of heights hI on left, and thus obtain height of step at A. Draw lines from A and F to V·. From n draw diagonal through O to G. Raise vertical at O to represent the height of the next step, its height being determined by the scale of heights at the side. From A and F draw lines to V·, and also similar lines from B, which will serve as guiding lines to determine the height of the steps at either end as we raise them to the required number.
Fig. 250.
Fig. 251.