How much square footage is in a circle 16 x 16 x 2?

Answer 1

A circle is a two dimensional shape whereas 16 x 16 x 2 has three dimensions and so cannot be a circle.

Perhaps you need to rethink that for which you are asking, and rephrase your question specifying a circle, eg of radius <whatever>, or of diameter <whatever>, or [very non-mathematical] that fits in a square <whatever> by <the_same_whatever>

Guessing, you may be giving the specifications of a paddling pool that fits in a square of 16 <some_unit> by 16 <of_the_same_unit> and is 2 <again_the_same_unit> high and want to know the area of the bottom of the pool.

In this case, the radius of the paddling pool will be 8 units and the area of ground that the bottom will cover is:

area_circle = π x radius2

= π x (8 units)2

= 64π square units

≈ 201.06 square units.