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如图,一个直径为6厘米的半圆,绕A点逆时针旋转60°,此时点B到了点B′.求图中阴影部分的面积.解由图可知:S1=S扇形-(S半圆-S弓形),
As shown in the figure, a semicircle with a diameter of 6 cm is rotated counterclockwise by 60 ° from point A to point B 'at point B. Find the area of the shaded area in the graph. -S bow),