求什么?
这是一组勾股数
a^2+b^2
=(m^2-n^2)^2+4m^2n^2
=m^4-2m^2n^2+n^4+4m^2n^2
=m^4+2m^2n^2+n^4
=(m^2+n^2)2
=c^2
是直角三角形