MathDB
projections of 4 points onto a plane are the vertices of a parallelogram

Source: ITAMO 1988 p5

February 2, 2020
3D geometryprojectionsparallelogramgeometry

Problem Statement

Given four non-coplanar points, is it always possible to find a plane such that the orthogonal projections of the points onto the plane are the vertices of a parallelogram? How many such planes are there in general?