Question

Need some help

Answer 1

53. The base of a solid is the circle
\[x^2+y^2=16\]
Find the volume of the solid given that the cross
sections perpendicular to the x − axis are: (a) squares, (b) equilateral triangles.

Answer 2

My thought process for determining the length of the square was
\[S=2\sqrt{16-x^2}\]

So I plugged that into \[\int\limits_{-4}^{4}(2\sqrt{16-x^2)^2}\] to find the volume.

What am I doing wrong here?