Given the information that the triangle has:

• Hypotenuse = 18
• Adjacent = $x$
• Opposite = $y$

We can assume that this is a right triangle, where the hypotenuse, adjacent, and opposite sides relate through the Pythagorean theorem. The Pythagorean theorem states:

$x^2 + y^2 = \text{hypotenuse}^2$

Substituting the value of the hypotenuse:

$x^2 + y^2 = 18^2$

$x^2 + y^2 = 324$

This is the equation we need to solve for the variables $x$ and $y$. However, without more information (such as an angle or ratio between $x$ and $y$), there are many possible pairs of values for $x$ and $y$ that satisfy this equation.

If we assume you want to find specific values for $x$ and $y$, please provide more information such as an angle or trigonometric relation, or specify any additional condition about the triangle.

Would you like to explore more, or provide any extra details?