Answer: all coplanar points equidistant from a given point
This is another way of saying "the set of all points that are equally distant from a fixed point" (eg: the set of all points 5 units away from some fixed point). The "fixed point" is the center of the circle. The distance from the center to any point on the circle is the radius.
The volume of a cylinder is written as V = πr²h. The volume is 324π cm³ and the height is 9 cm. Evaluating it, we will arrive at the value of radius as 6 cm. Area of the base can be obtained using the formula A = πr². If r = 6cm, area of the base will be 36π cm