# Euler's four-square identity

> product of sums of four squares is a sum of four squares

**Wikidata**: [Q1149225](https://www.wikidata.org/wiki/Q1149225)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Euler's_four-square_identity)  
**Source**: https://4ort.xyz/entity/euler-s-four-square-identity


## References

1. Freebase Data Dumps. 2013