Resposta :
[tex]\text{menor hipotenusa} \rightarrow x_1\\\text{hipotenusa do meio} \rightarrow x_2\\\text{maior hipotenusa} \rightarrow x\\\\x_1^2=2^2+1^2\\x_1^2=4+1\\x_1=\sqrt{5}\\\\\\x_2^2=(\sqrt{5})^2+2^2\\x_2^2=5+4\\x_2=\sqrt{9}=3\\\\\\x^2=3^2+4^2\\x^2=25\\x=5[/tex]