The accurate depiction of shades and shadows in orthographic views is important in architectural design for various reasons. It is an important device to understand some of the three-dimensional qualities of a design, particularly an elevation, in what is a purely two-dimensional drawing.
When I drow the ortographic views of ladder, I drew a line wrong, so occured a shadow that does not exist. After that, I learned correct drawing from my instructer. My advice to you, you must be carefull to draw 🙂