To find side $ a $ use formula:
$$ V = \dfrac{ a ^{ 2 } \cdot h }{ 3 } $$After substituting $V = 198.4\, \text{cm}$ and $h = 9.3\, \text{cm}$ we have:
$$ 198.4\, \text{cm} = \dfrac{ a ^{ 2 } \cdot \left( 9.3\, \text{cm} \right)^{4} }{ 3 } $$$$ 198.4\, \text{cm} \cdot 3 = a ^{ 2 } \cdot \left( 9.3\, \text{cm} \right)^{4} $$$$ 595.2\, \text{cm} = 9.3\, \text{cm} \cdot a ^{ 2 } $$$$ a ^{ 2 } = \dfrac{ 595.2\, \text{cm}}{ 9.3\, \text{cm} } $$$$ a ^{ 2 } \approx 20.3718 $$$$ a \approx \sqrt{ 20.3718 } $$$$ a \approx 4.5135 $$