Answer:
x = √80
Explanation:
Let's find the hypotenuse of the top side triangle.
Using the Pyth. Theorem:
Let y be the hypotenuse of the top side triangle:
2^2 + 4^2 = y^2
y = √20
Now, the rectangle facing us is formed by two indentical triangles, therefore the bottom side of the triangle is also y = √20 .
Using the Pyth.Theorem again, we can find x:
x^2 + (√20)^2 = 10^2
x = √80 .