Answer:
6.4
Step-by-step explanation:
The Pythagorean Theorem says that in a right triangle,
[tex](\text{leg})^2+(\text{leg})^2=(\text{hypotenuse})^2[/tex].
In this problem,
[tex]a^2+b^2=c^2\\\\4^2+5^2=c^2\\\\16+25=c^2\\\\41=c^2\\\\c=\sqrt{41} \approx 6.4[/tex]
