\[- 405 + 6y^{2} - 9y = 0\ \ \ \ \ \ \ |\ :3\]
\[2y^{2} - 3y - 135 = 0\]
\[D = ( - 3)^{2} - 4 \cdot 2 \cdot ( - 135) =\]
\[= 9 + 1080 = 1089;\ \ \ \ \sqrt{D} = 33.\]
\[y_{1} = \frac{3 + 33}{2 \cdot 2} = \frac{36}{4} = 9;\ \ \ \]
\[\text{\ \ }y_{2} = \frac{3 - 33}{2 \cdot 2} = \frac{- 30}{4} =\]
\[= - 7\frac{1}{2}\ \ \ (не\ подходит).\]
\[x = \frac{270}{9} = 30.\]
\[Ответ:9\ см\ и\ 30\ см.\]