Solution: The cosine of \(45^\circ\) is given by \(\cos 45^\circ = \frac\sqrt22\). For a square with side length \(s = 7\) units, the length of the diagonal \(d\) can be calculated using the Pythagorean theorem: \(d = s\sqrt2\). Substituting the value of \(s\), we get \(d = 7\sqrt2\). Therefore, the length of the diagonal is \(\boxed7\sqrt2\). - Veritas Home Health