If the central angle of a fan is doubled and the radius is reduced to 1/2, what is the ratio of the area of the fan to the area of the original fan?
如果一个扇形的圆心角扩大为原来的2倍，半径长缩小为原来的(1/2)，那么所得扇形的面积与原来扇形的面积的比值是多少
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>