To find height $ h $ use formula:
$$ V = \dfrac{ r ^{ 2 } \cdot h \cdot \pi}{ 3 } $$After substituting $ V = 226.08 $ and $ r = 6 $ we have:
$$ 226.08 = \dfrac{ 6 ^{ 2 } \cdot h \cdot \pi}{ 3 } $$$$ 226.08 \cdot 3 = 6 ^{ 2 } \cdot h \cdot \pi $$$$ 678.24 = 36 \cdot h \cdot \pi $$$$ h = \dfrac{ 678.24 }{ 36 \, \pi} $$$$ h = 5.997 $$