GWD-2 GMAT Q5的疑问

mahat

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
图略.答案是A,我认为是D.请大家看我的推导有错误吗?

因为(R-r)=AC-AB=BC,同时(R-r)=(R+BC)-r-BC,  R+BC=CE+BC=BE=BD+DE=r+DE,所以(R-r)=DE-BC 所以DE-BC=BC,就可以推出BC和AB

ring_cheng

好像有过讨论的，请楼主找找：

http://forum.chasedream.com/dispbbs.asp?boardID=22&ID=58619&page=1

wside

yeah ,D is the correct answer