I need help with this question

Answer:
x = (3√2)/2
Step-by-step explanation:
In the isosceles right triangle the side lengths have the ratio ...
1 : 1 : √2
This means the short leg (x) is 1/√2 times the length of the hypotenuse. You want the ratio with a rational denominator, so you need to multiply numerator and denominator by √2.
[tex]x=3\cdot\dfrac{1}{\sqrt{2}}=3\cdot\dfrac{\sqrt{2}}{(\sqrt{2})^2}\\\\\boxed{x=\dfrac{3}{2}\sqrt{2}}[/tex]