This is a drawing on Geogebra of a perspectivity. In geometry, a perspectivity is the formation of an image (points on diagonal line) in a plane of a scene (points on straight line) viewed from a fixed point. The science of perspectivity uses them to make realistic images in the proper proportion. You can move any point (except F1, F2, G1, G2, I1, I2, H1, and H2) around and explore. The triangle point is the point of perspectivity, where you would be seeing the object from.