If the radius of a circle is reduced from 8 cm to 6 cm, how much is its area reduced?
圆的半径由8厘米减少到6厘米，则它的面积减少了多少
<gadget id="calculator">64 - 36</gadget>
<output>28</output>

<gadget id="calculator">28 / 64</gadget>
<output>7/16 = around 0.4375</output>

<result>7/16 = around 0.4375</result>