Cut off a sector from a circle with a central angle of 60 degrees equal to its radius, what is the area of the cut sector equal to the area of the remaining sector?
在一个圆里剪去一个与它半径相等的圆心角为60度的扇形，剪去的扇形面积是剩下扇形面积的多少
<gadget id="calculator">360 - 60</gadget>
<output>300</output>

<gadget id="calculator">60 / 300</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>