Volume suatu kerucut 154cm³.jika tinggi kerucut 12 cm dan phi 22/7 maka hitunglah jari-jari alasnya

V = 1/3 π r² t
[tex]r ^2= \frac{3V}{\pi t} = \frac{3\times 154}{22/7\times 12}= \frac{49}{4} \\ \\ r = \sqrt{ \frac{49}{4} } = \frac{7}{2} =3.5\,cm[/tex]