find a point of convex ABCD so that it's projections on sides are vertices of #
Source: Sharygin Geometry Olympiad 2015 Final 9.2
August 1, 2018
geometryparallelogramconstructionprojection
Problem Statement
A convex quadrilateral is given. Using a compass and a ruler construct a point such that its projections to the sidelines of this quadrilateral are the vertices of a parallelogram.(A. Zaslavsky)