If the radius of the circle increases from 4 decimeters to 6 decimeters, the area of the circle increases by how many square decimeters.
圆的半径由4分米增加到6分米，圆的面积增加了多少平方分米．
<gadget id="calculator">6 ** 2</gadget>
<output>36</output>

<gadget id="calculator">3.14 * 36</gadget>
<output>113.04</output>

<gadget id="calculator">4 ** 2</gadget>
<output>16</output>

<gadget id="calculator">3.14 * 16</gadget>
<output>50.24</output>

<gadget id="calculator">113.04 - 50.24</gadget>
<output>62.8</output>

<result>62.8</result>