Answer:
x = sqrt(147)
Explanation:
This is a right triangle, so we can use the Pythagorean theorem.
a^2 + b^2 = c^2 where a and b are the legs and c is the hypotenuse.
x^2 +7^2 = 14^2
x^2 +49 = 196
Subtract 49 from each side
x^2 = 147
Take the square root of each side
sqrt(x^2) = sqrt(147)
x = sqrt(147)