The central angle of a sector is 40°, and the area of the sector is equal to the area of the circle on which it is located. (fill in a fraction)
扇形的圆心角是40°，这个扇形的面积是所在圆的面积的多少．(填几分之几)
<gadget id="calculator">40 / 360</gadget>
<output>1/9 = around 0.111111</output>

<result>1/9 = around 0.111111</result>