[tex]Volume\ of\ the\ cone:V=\frac{1}{3}\pi r^2H\\\\r=3cm\to r^2=9cm^2;\ H=4cm\\\\therefore\ V=\frac{1}{3}\cdot\pi \cdot9\cdot4=\left(\frac{1}{3}\cdot36\right)\pi=12\pi\ (cm^3)\\------------------------\\\\\pi\ is\ an\ irrational\ number:\pi=3.14159265359...\approx3.14\\\\therefore\\\\12\pi\approx12\cdot3.14=37.68\approx\boxed{37.7\ (cm^3)}\leftarrow answer[/tex]
