Answer:
[tex]L=4\sqrt{15}\ m[/tex]
or
[tex]L=15.49\ m[/tex]
Step-by-step explanation:
we know that
Applying the Pythagorean Theorem in the rectangular pool
[tex]d^2=L^2+W^2[/tex]
where
d is the diagonal of the pool
L is the length of the pool
W is the wide of the pool
we have
[tex]d=16\ m\\W=4\ m[/tex]
substitute the given values
[tex]16^2=L^2+4^2[/tex]
solve for L
[tex]L^2=16^2-4^2\\L^2=240\\L=\sqrt{240}\ m[/tex]
simplify
[tex]L=4\sqrt{15}\ m[/tex]
or
[tex]L=15.49\ m[/tex]