由(m²-1)^2=m^4-2m^2+1,
(2m)^2=4m^2,
(m²+1)^2=m^4+2m^2+1,
显然m^4-2m^2+1+4m^2=m^4+2m^2+1,
即(m²-1)^2+ (2m)^2= (m²+1)^2
所以这个三角形是直角三角形