宽是长的1/2，圆的半径是3厘米。求阴影部分面积。+f7c+_5V6O+S:Z'N4J
+f7c+_5V6O+S:Z'N4J
算式：提示'S;N3F-M+f7c+_5V6O+S:Z'N4J
答：阴影部分面积是/k4y)C2y2X2f8D;l,[.n'~平方厘米。+f7c+_5V6O+S:Z'N4J