If the radius of a circle with a radius of 4 cm is increased by 2 cm, find the area of the increased part.
把一个半径为4厘米的圆的半径增加2厘米，求增加部分的面积．
<gadget id="calculator">4 + 2</gadget>
<output>6</output>

<gadget id="calculator">6 ** 2</gadget>
<output>36</output>

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

<gadget id="calculator">36 - 16</gadget>
<output>20</output>

<gadget id="calculator">3.14 * 20</gadget>
<output>62.8</output>

<result>62.8</result>