Question 190737
<pre><font size = 4 color = "indigo"><b>
{{{drawing(300,300,-4,4,-5,4,
rectangle(-4,-3.5,4,4),
circle(0,-.5,2),
locate(-2,2,d),
locate(-3.5,-2,k)
locate(0,-2.7,C),
locate(-.3,-1,j),
locate(1.1,.4,i), 
circle(sqrt(2),sqrt(2),2), 
locate(-3.5,2.5,A),
circle(-sqrt(2),sqrt(2),2),
locate(3.5,2.5,B),
locate(-1.3,.5,g),
locate(0,2.5,e),
locate(2,2,h),
locate(-.2,1.1,f) )}}}
 
A is made up of 4 regions d, e, f, and g

Why 4?  Because 
1. d is the part of A which is not part of B or C,
2. e is the part of A which is also part of B but not part of C.
3. g is the part of A which is also part of C but not part of B.
4. f is the part of A which is also part of B and C.

That's all you asked but you need to know the
following as well:

B is made up of 4 regions e, f, h, and i
C is made up of 4 regions f, g, i, and j

Region d is part of A but is not part of B or C
Region h is part of B but is not part of A or C
Region j is part of C but is not part of A or B

Region e is part of A and B, but is not part of C
Region g is part of A and C, but is not part of B
Region i is part of B and C, but is not part of A

Region f is part of A, part of B, and part of C

Region k is not part of any of A, B or C.




Edwin</pre>