梯形高= 3 + 4 = 7
梯形面积= (3 + 4 ) X 7 ÷ 2 = 24.5
三角形面积= 4 X 4 ÷ 2 = 8
四分之一圆面积 = 3 X 3 X 3.14 ÷ 4 = 7.065
阴影面积= 24.5 - 8 - 7.065 =9.435
梯形高= 3 + 4 = 7
梯形面积= (3 + 4 ) X 7 ÷ 2 = 24.5
三角形面积= 4 X 4 ÷ 2 = 8
四分之一圆面积 = 3 X 3 X 3.14 ÷ 4 = 7.065
阴影面积= 24.5 - 8 - 7.065 =9.435