六上数学期末必考【求阴影面积】三大类型 题型一:整体----部分性 S阴影=s圆-S三角形 S阴影=S长方形-S圆 x3. 14x(6÷2)²-6x3÷2 8x12-x3. 14x (8+2)² =3. 14x4. 5-9 =96-3.14x8 =5.13(cm)² =70. 88 (cm)² S阴影=2x(S正方形-S圆) S阴影=S大圆-S小圆 20÷2=10cm 3.14x6-3. 14x (6+2)² 2x (10x10-x3.14x10²) =3. 14x36-3.14x9 =2x(100-78. 5) =84. 78 (cm)² =43 (cm)²