LAST ATTEMPT IM MARKING AS BRAINLIEST!! ( Pythagorean theorem )

Answer:
x=sqrt(7)
Step-by-step explanation:
Since this is a right triangle, 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 + ( sqrt(7))^2 = (sqrt(14))^2
x^2+7 = 14
x^2 = 14-7
x^2 = 7
Take the square root of each side
sqrt(x^2) = sqrt(7)
x=sqrt(7)