Answer:
Step-by-step explanation:
We have to use Pythagorean's Theorem twice here, first to find the length of the dotted line, which I will call h, and then again to find x. First we need to find h so we can use it to find x:
[tex](2\sqrt{5})^2=4^2+h^2[/tex] and
[tex]20=16+h^2[/tex] and
[tex]4=h^2[/tex] so
h = 2. Then again:
[tex]x^2=2^2+22^2[/tex] and
[tex]x^2=4+484[/tex] and
[tex]x^2=488[/tex] so
x = 2√122
