If a = 4 and b = 8 are the legs and c is a hypotenuse then:
[tex]a^2+b^2=c^2[/tex]
Substitute:
[tex]c^2=4^2+8^2\\\\c^2=16+64\\\\c^2=80\to c=\sqrt{80}\\\\c=\sqrt{16\cdot5}\to c=4\sqrt5[/tex]
If a = 4 and c are the legs and b = 8 is hypotenuse, then:
[tex]a^2+c^2=b^2[/tex]
Substitute:
[tex]4^2+c^2=8^2\\\\16+c^2=64\ \ \ |-16\\\\c^2=48\to c=\sqrt{48}\\\\c=\sqrt{16\cdot3}\to c=4\sqrt3[/tex]
