Shadows onto walls

Figure 1 : Shadow of a post AB on a wall : Draw lines from T through A to create R, draw vertical line to R, draw line from S through B to create N: The lines AR and RN present the shadow of the post AB.

Figure 2 : Shadow of a balcony : Create W and draw line to V. Draw a vertical line to VW at any point (Q) to create P as crossing-point with VY, draw a line from T through Q to create R, draw a vertical line to UV through R to create G as crossing-point with a line through S and P : The line passing through V and G presents the shadow-line of the balcony.

Figure 3 : Shadow of a post onto a beam : Draw line from T through A and from S through B to create W. Draw vertical line through P to create N, draw line from N to T to create R : RN and VW present the shadows of the post AB.