Final answer:
Lines that belong to the same plane and never intersect are known as parallel lines. They have a constant slope and maintain a consistent distance apart, unlike orthogonals in art, which appear to converge at a vanishing point in linear perspective.
Step-by-step explanation:
In mathematics, lines that belong to the same plane and never intersect are called parallel lines. These lines maintain a constant distance from each other and have the same slope. This concept is not to be confused with orthogonals, which are lines used in the art technique of linear perspective that converge at the vanishing point to suggest the illusion of depth. Parallel lines, due to their nature, never meet, even if extended infinitely. Whereas orthogonal lines, in the context of linear perspective, appear to converge in the distance as part of an optical illusion.