Linear perspective drawing is the art of creating the illusion of depth on the flat surface of the sketch. In perspective, all the objects seem to gradually decrease in size when the distance between them and viewer increase. And each of the sets of parallel lines coming out from the objects in the sketch appears to meet at one particular point.

Speaking of linear perspective, we have to notice: this system we generally apply to the box-like objects. I mean the rectangular boxes. So we use it for drawing the rooms with furniture and, of course, the streets with buildings - city landscapes.

All the boxes, surrounding us in daily life, usually are standing on the horizontal surfaces, horizontal planes. And how they look depends on our position, more precisely, on the level of our eyes. Level of eyes is a horizontal plane too, but we see it as a line. This line we call the line of the horizon.