KnowraLagrange's four-square theoremLinked fromLinked fromThe 10 pages that link to Lagrange's four-square theorem, each with the reason it gives.All 10Broader topic 3Related 2Compared with 5Waring's problemRelated: It illustrates a universal representation theorem for one exponent.Euler's four-square identityRelated: Euler's identity supplies the multiplication principle used in the history of four-square results.