设小圆半径5X,大圆半径7X,则有:
3.14*(7X)^2-3.14*(5X)^2=28.26
24X^2=9
X^2=9/24
则大圆面积是3.14*(7X)^2=3.14*49*X^2=3.14*49*9/24=57.6975平方米
比小圆面积多的百分比是=(7^2-5^2)/(5^2)=96%
设小圆半径5X,大圆半径7X,则有:
3.14*(7X)^2-3.14*(5X)^2=28.26
24X^2=9
X^2=9/24
则大圆面积是3.14*(7X)^2=3.14*49*X^2=3.14*49*9/24=57.6975平方米
比小圆面积多的百分比是=(7^2-5^2)/(5^2)=96%