Answer:
4 sqrt(5)
Explanation:
We can use the Pythagorean theorem to find x
a^2 +b^2 = c^2
where a and b are the legs and c is the hypotenuse
8^2 +4^2 = x^2
64+16 = x^2
80 = x^2
Take the square root of each side
sqrt(80) = sqrt(x^2)
We know that sqrt(ab) = sqrt(a)sqrt(b)
sqrt(16) sqrt(5) = x
4sqrt(5) = x