Y by
A circle with radius
and a circle with radius
have the same center. The area of the small circle we call
. The area of the ring bounded by both circles we call
. The triangle
is right. A straight line cuts the hypotenuse
perpendicularly
and cuts
into
. Take
such that
. The area of
we call
and the area of the quadrilateral
we call
. Prove that
if and only if
.





![$[V W]$](http://latex.artofproblemsolving.com/4/f/a/4fa109038266e0fa7dbb9c20c644548b7e57fb91.png)

![$[UW]$](http://latex.artofproblemsolving.com/e/d/9/ed9d18cd1e42db3bf822bc21c30e8ded0d07edf8.png)









This post has been edited 4 times. Last edited by parmenides51, Dec 23, 2022, 7:23 PM