To apply the Pythagorean Theorem in a right triangle, you use the formula:
\[ a^2 + b^2 = c^2 \]
where \( c \) is the length of the hypotenuse (the longest side), and \( a \) and \( b \) are the lengths of the other two sides.
However, you haven't provided the lengths of the sides of the triangle. Could you please share those values so we can find the unknown side length together?