English: Proof without words of Varignon's theorem by CMG Lee.
1. An arbitrary quadrilateral and its diagonals.
2. Bases of similar triangles are parallel to the blue diagonal.
3. Ditto for the red diagonal.
4. The base pairs form a parallelogram with half the area of the quadrilateral, Aq, as the sum of the areas of the four large triangles, Al is 2 Aq (each of the two pairs reconstructs the quadrilateral) while that of the small triangles, As is Al/4 (half linear dimensions yields quarter area) = Aq/2, and the area of the parallelogram is Aq − As = Aq − Aq/2 = Aq/2.
to share – to copy, distribute and transmit the work
to remix – to adapt the work
Under the following conditions:
attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled GNU Free Documentation License.http://www.gnu.org/copyleft/fdl.htmlGFDLGNU Free Documentation Licensetruetrue
You may select the license of your choice.
Captions
Add a one-line explanation of what this file represents
{{Information |description ={{en|1=Proof without words of Varignon's theorem by CMG Lee. 1. An arbitrary quadrilateral and its diagonals. 2. Bases of similar triangles are parallel to the blue diagonal. 3. Ditto for the red diagonal. 4. The base pairs form a parallelogram with half the area of the quadrilateral, ''A<sub>q</sub>'', as the sum of the areas of the four large triangles, ''A<sub>l</sub>'' is 2 ''A<sub>q</sub>'' (each of the two pairs reconstructs the quadrilateral) while tha...
This file contains additional information, probably added from the digital camera or scanner used to create or digitize it.
If the file has been modified from its original state, some details may not fully reflect the modified file.
Short title
Varignon parallelogram
Image title
Proof without words of Varignon's theorem by CMG Lee. 1. An arbitrary quadrilateral and its diagonals. 2. Bases of similar triangles are parallel to the blue diagonal. 3. Ditto for the red diagonal. 4. The base pairs form a parallelogram with half the area of the quadrilateral, Aq, as the sum of the areas of the four large triangles, Al is 2 Aq (each of the two pairs reconstructs the quadrilateral) while that of the small triangles, As is a quarter of Al (half linear dimensions yields quarter area), and the area of the parallelogram is Aq minus As.