
Area and Volume
The base of a solid is a circle with radius 6. The cross sections of the solid perpendicular to a fixed diameter of the base are squares.
If the circle is centered at the origin and the cross sections are perpendicular to the xaxis, find the area A(x) of the cross section at x and find the volume V of the solid.
(Headbang)

Well if the cross sections are squares then the length of each side is equal to line drawn across the circle.
For example, at x=0, the bottom line of the area goes through the middle of the circle, so the
area of the cross section is equal to $\displaystyle 2(r+r)=4r=4\cdot6$
Can you visualize the shape ?
Can you now find the term for a general x?
Use the fact that this object is highly symmetrical.
Hope that helps.

So are you saying that I would need to use y= sqrt((r^2)(x^2)) with r = 6?
And then, would I have to multiply by 2 for the other side of the circle and finally square the entire thing to find the area equation?

Yes that is excatly what I am saying.