Subtract a circular piece of paper with a diameter of 8 cm from a semicircle of paper with a radius of 8 cm, what is the remaining area?
在半径为8厘米的半圆形纸中减去一个直径为8厘米的圆形纸片，剩下的面积为多少？
<gadget id="calculator">8 ** 2</gadget>
<output>64</output>

<gadget id="calculator">64 / 2</gadget>
<output>32</output>

<gadget id="calculator">3.14 * 32</gadget>
<output>100.48</output>

<gadget id="calculator">8 / 2</gadget>
<output>4</output>

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

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

<gadget id="calculator">100.48 - 50.24</gadget>
<output>50.24</output>

<result>50.24</result>