how do we do thi sone laswt nraionlyu tutor got this wronmg its a,b,mc

Given:
A rectangle is inscribed inside the isosceles right triangle. The length of the hypotenuse of the right triangle is 14 units.
Required:
Express the y -coordinate of P in terms of x.
Explanation:
Let the other equal side of the right triangle is x unit.
Use the Pythagorean theorem as:
[tex]\begin{gathered} (hyp.)^2=(opp.)^2+(adj.)^2 \\ (14)^2=(x)^2+(x)^2 \\ 196=x^2+x^2 \\ 196=2x^2 \end{gathered}[/tex]Find the value of x as:
[tex][/tex]