EntityQ325978· pop 15· linked from 232 articlescongruent numberSign in to savepositive integer that is the area of a right triangle with three rational number sidesConnectionsprime numberEntityfigurate numberEntityautomorphic numberEntityareaEntityInternational Standard Book NumberEntitynatural numberEntityintegerEntitynumber theoryEntityrational numberEntityFibonacciEntityPierre de FermatEntitydigital object identifierEntitybinary numeral systemEntitydigitEntityexponentiationEntitynumeral systemEntitygroupEntityright triangleEntitythree-dimensional spaceEntityhypotenuseEntityCategoriesArithmetic problems of plane geometryElliptic curvesTriangle geometryUnsolved problems in number theory