Answer:
[tex]2\sqrt{77}[/tex]
Step-by-step explanation:
Use the Pythagorean theorem. [tex]a^{2} +b^{2}=c^{2}[/tex]
a and b are the two side lengths
c is the hypotenuse (value across from the right angle)
Plug in the values that you are given.
[tex]a^{2} +4^{2} =18^{2}[/tex]
Solve for x
[tex]x^{2} =18^{2} -4^{2}[/tex]
[tex]x^{2} =308[/tex]
x=[tex]\sqrt{308}[/tex]
[tex]x=2\sqrt{77}[/tex]
