A rope 62.8 decimeters long just wraps around a tree, what is the cross-sectional area of the part where the tree is wound?
一根62.8分米长的绳子刚好绕一棵树一周，这棵树所绕部位的横截面积是多少？
<gadget id="calculator">62.8 / 3.14 / 2</gadget>
<output>10</output>

<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

<gadget id="calculator">3.14 * 100</gadget>
<output>314</output>

<result>314</result>