AMC 8 2024 Problem 18
AMC8 2024 年第 18 题
圆★★★☆☆
Three concentric circles centered at O have radii of 1, 2, and 3. Points B and C lie on the largest circle. The region between the two smaller circles is shaded, as is the portion of the region between the two larger circles bounded by central angle ∠BOC, as shown in the figure below. Suppose the shaded and unshaded regions are equal in area. What is the measure of ∠BOC in degrees?
以点 O 为圆心的三个同心圆的半径分别为 1、2、3。点 B 和点 C 位于最大圆上。两个较小圆之间的区域被涂上阴影，两个较大圆之间且位于圆心角 ∠BOC 内的区域也被涂上阴影，如图所示。若阴影区域与非阴影区域面积相等，请问 ∠BOC 的度数是多少？
- A.108
- B.120
- C.135
- D.144
- E.150
正确答案 · Correct Answer
A
解析 · Solution
解析整理中
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