The correct statement identifying Hank's error is:
He did not set up the Pythagorean Theorem correctly. The hypotenuse should be isolated on one side of the equation.
In the context of the Pythagorean theorem (a² + b² = c²), Hank appears to have made mistakes in his algebraic manipulations, leading to incorrect equations and results. The hypotenuse should indeed be isolated correctly to find its actual length.