STEP 1: find side $ a $
To find side $ a $ use formula:
After substituting $B = 42\, \text{cm}$ we have:
$$ B = a^2 $$ $$ a^2 = 42\, \text{cm} $$ $$ a = \sqrt{ 42\, \text{cm} } $$STEP 2: find volume $ V $
To find volume $ V $ use formula:
$$ V = \dfrac{ a ^{ 2 } \cdot h }{ 3 } $$After substituting $a = \sqrt{ 42 }\, \text{cm}^0$ and $h = 14\, \text{cm}$ we have:
$$ V = \dfrac{ 42 \cdot 14\, \text{cm} }{ 3 }$$$$ V = \dfrac{ 588\, \text{cm} }{ 3 } $$$$ V = 196\, \text{cm} $$