选择题
2015 AMC 8 Problem 2: Shaded Octagon Fraction
Point O is the center of regular octagon ABCDEFGH, and X is the midpoint of side AB. What fraction of the area of the octagon is shaded?
2015 AMC 8 第2题 ：阴影八边形分数
点O是正八边形ABCDEFGH的中心， X是AB侧的中点。八边形面积的哪一部分是阴影？
A.
11/32
B.
3/8
C.
13/32
D.
7/16
E.
15/32