The figure formed when the midpoints of adjacent sides of a quadrilateral are joined. Varignon's theorem demonstrated that this figure is a parallelogram. The center of the Varignon parallelogram is the geometric centroid of four point masses placed on the vertices of the quadrilateral.
Varignon Parallelogram
See also
Bimedian, Midpoint, Midpoint Polygon, Parallelogram, Quadrilateral, Varignon's TheoremExplore with Wolfram|Alpha
References
Coxeter, H. S. M. and Greitzer, S. L. Geometry Revisited. Washington, DC: Math. Assoc. Amer., p. 53, 1967.Referenced on Wolfram|Alpha
Varignon ParallelogramCite this as:
Weisstein, Eric W. "Varignon Parallelogram." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/VarignonParallelogram.html