Algebra 2 (1st Edition)

$d^2\gt\frac{25}{9}h^2$
We know that $w\gt \frac{4}{3}h$ and that by the Pythagorean Theorem, $d^2=w^2+h^2$. Hence $d^2=w^2+h^2\gt(\frac{4}{3}h)^2+h^2=\frac{16}{9}h^2+h^2=\frac{25}{9}h^2$