\[\boxed{\text{4.\ 251}}\]
\[V_{цилиндра} = \pi R^{2} \cdot h\]
\[V_{конуса} = \frac{1}{3}\pi R^{2} \cdot h\]
\[\pi R^{2} \cdot h_{1} = \frac{1}{3}\pi R^{2} \cdot h_{2}\]
\[h_{1} = \frac{\frac{1}{3}\pi R^{2} \cdot h_{2}}{\pi R^{2}}\]
\[h_{1} = \frac{1}{3}h_{2}\]
\[h_{1} = \frac{1}{3} \cdot 36 = 12\ (см).\]
\[Ответ:высота\ цилиндра\ 12\ см.\]