To find height $ h $ use formula:
$$ V = \dfrac{ a ^{ 2 } \cdot h }{ 3 } $$After substituting $V = 2592100\, \text{cm}$ and $a = 210\, \text{cm}$ we have:
$$ 2592100\, \text{cm} = \dfrac{ 210\, \text{cm} ^{ 2 } \cdot h }{ 3 } $$$$ 2592100\, \text{cm} \cdot 3 = 210\, \text{cm} ^{ 2 } \cdot h $$$$ 7776300\, \text{cm} = 44100\, \text{cm}^2 \cdot h $$$$ h = \dfrac{ 7776300\, \text{cm} }{ 44100\, \text{cm}^2 } $$$$ h = \frac{ 529 }{ 3 }\, \text{cm}^-1 $$