Given:
Height of the cylindrical pillar = 9 cm
Volume = 324π cm³
Recall,
Area of the circle (Base of the cylindrical pillar):
![\text{ Area = }\pi\text{r}^2](https://img.qammunity.org/2023/formulas/mathematics/college/9a51mwwhn2beio270t9lt4ik3o6dmg5qpa.png)
Volume of a cylinder:
![\text{ Volume = }\pi\text{r}^2h](https://img.qammunity.org/2023/formulas/mathematics/college/zkoerbryrkz4pvtj58m7ym192rmwng71gg.png)
In other words, the formula for the pillar's volume will be:
![\text{ Volume = (Area of Pillar's base) x Height}](https://img.qammunity.org/2023/formulas/mathematics/college/sjh9g417n4aihzvgjjlfcjm1jyazrp89th.png)
Where,
r = radius
h = height of the pillar
Thus, we get:
![\text{ 324}\pi\text{ = (Area of Pillar's base) x 9}](https://img.qammunity.org/2023/formulas/mathematics/college/do45wbm1ncumahpxpem0mmjaobvkr7r49l.png)
![\text{ }\frac{\text{324}\pi}{\text{ 9}}\text{ =}\frac{\text{ (Area of Pillar's base) x 9}}{\text{ 9}}](https://img.qammunity.org/2023/formulas/mathematics/college/w0jimdqnqx3ahu7jbk3heqflftdgr1fi42.png)
![\text{ 36}\pi\text{ = Area of Pillar's base}](https://img.qammunity.org/2023/formulas/mathematics/college/dizuetjajpbhcgr18tkc0yoj325ismnjzh.png)
ANSWER: 36π cm²