Mental Stretch

[bagwa-john]

Addendum, if I may.

It would appear that in a problem such as this, for any two concentric circles with a connecting chord where the chord of the outer circle is tangent to the inner circle; and we want to find the area of the outer circle minus the inner circle;
Going to the minimum side of the limit as we found in the previous problem, we can treat the chord length as the diameter of a circle with the same area.

It seems so easy after the fact! I'd been looking for a general formula for this, and thought I'd post it.

I'm a three dimensional geometry nut. Finding lengths of edges within a given structure based on little information is what I have to do to build the sculptures I do.

Cheers!