1901/02/01 by R. F. Muirhead · 1 citation
Mathematics · Engineering · #Mathematics and Applications #History and Theory of Mathematics #Robotic Mechanisms and Dynamics #Parallelogram #Rhombus #Isosceles triangle #Geometry #Ellipse #Equidistant #Midpoint #Line (geometry) #Mathematics #Combinatorics #Point (geometry) #Physics
paper · pdf · doi:10.1017/s0013091500032892
openalex publication_date 1901/02/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/03
In Figure 11 let ABCD be a contraparallelogram having AB = CD, AD = BC. Let O, P, Q, R be the midpoints of AB, BC, AD, DC respectively. They obviously lie in the line parallel to AC and to BD, and equidistant from them. Let U be the mid-point of AC and V that of BD. OURV is a rhombus each of whose sides is half of AD or BC, and parallel to AD or BC. PUQV is a rhombus each of whose sides is half of AB or CD, and parallel to AB or CD.