D
· ·
B C
A E
In the figure, points A, B, C, D, and E lie on a line. A is on both circles, B is the center of the smaller circle, C is the center of the larger circle, D is on the smaller circle, and E is on the larger circle. What is the area of the region inside the larger circle and outside the smaller circle?
(1) AB = 3 and BC =2
(2) CD =1 and DE = 4
the key is A.
but my question is: if cd= 1 , de= 4, then R for Big Circle is CE=5=CA, then r for small circle should be (ca+cd)/2=3=ab,
then the area should be (25pai-9pai)=16pai.
so why the key is not D?
Thx | 
