# van Aubel's theorem

> theorem that, given a convex quadrilateral, if one constructs a square—external to the quadrilateral—on each side, the 2 line segments between the centers of opposite squares have equal lengths and are orthogonal

**Wikidata**: [Q594571](https://www.wikidata.org/wiki/Q594571)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Van_Aubel's_theorem)  
**Source**: https://4ort.xyz/entity/van-aubel-s-theorem


## References

1. Freebase Data Dumps. 2013