六上数学《圆的阴影部分面积》12类型 面积:3.14×(4÷2)²-4×4÷2 =3.14×4-16÷2 =12.56-8 =4.56 面积:6²×3.14×12-6×6 =36×3.14×12-36 =56.52-36 =20.52 面积:2×2-(2÷2)²×3.14 =4-1²×3.14 =4-3.14 =0.86 面积:2×2-(2÷2)²×3.14 =4-1²×3.14 =4-3.14 =0.86