To find volume $ V $ use formula:
$$ V = h ^{ 2 } \cdot r \cdot \pi$$After substituting $r = 2\, \text{cm}$ and $h = 4\, \text{cm}$ we have:
$$ V = 4\, \text{cm} ^{ 2 } \cdot 2\, \text{cm} \cdot \pi$$$$ V = 16\, \text{cm}^2 \cdot 2\, \text{cm} \cdot \pi $$$$ V = 32\pi\, \text{cm}^3 $$