题目

On each side of a unit square,an equilateral triangle of side length 1 is constructed.On each new side of each equilateral triangle,another equilateral triangle of side length 1 is constructed.The interiors of the square and the 12 triangles have no points in common.Let R be the region formed by the union of the square and all the triangles,and let S be the smallest convex polygon that contains R.What is the area of the region that is inside S but outside
A 1/4 B √2/4 C 1 D√3 E 2√3

提问时间：2021-04-01

答案

答案是A,其实画个图就清楚了,边长为1的正方形（unit square) 连同周边12个正三角形组成一个新的边长为2的正方形,要使包在正方形外面的八边形面积最小,只有A是正确的,BCEDE的话面积都比1/4的时候大.