Linear Perspective

Linear Perspective is a mathematical way of creating an illusion of space/distance on a flat surface

Horizontal Line - A horizontal line is drawn across the surface mostly represents where the sky meets the ground

Vanishing Point - A point where all parallel lines that go away from the viewer disappear to one point

Orthogonal Lines - Straight diagonal lines to connect points around the edges of a picture to create depth

Transversal Lines - Are perpendicular to orthogonal lines, parallel to horizontal line, form the close and far edges of a rectangle

One Point Perspective - Uses one vanish point to draw an object

Two Point Perspective - Uses two vanishing points to draw an object

You can show depth/perspective by the size of an object, and the shades, or light variation it has. Atmospherical/aerial perspective makes objects at a distance, (mountain in this case) have a tint more to what the atmosphere is (most of the time blue). Leonardo's rule is to paint the first object normal color, the next one back with a slightly blue tint, and get bluer as you go further back with more vague detail. At perspective, a circle is an ellipse which is formed within the confines of a rectangle.