Xiao Gang measured the circumference of a tree trunk to be 188.4 cm. What is the area of the cross-section of the tree trunk?
小刚量得一棵树干的周长是188.4厘米．这棵树干的横截面的面积是多少？
<gadget id="calculator">188.4 / 3.14 / 2</gadget>
<output>30</output>

<gadget id="calculator">30 ** 2</gadget>
<output>900</output>

<gadget id="calculator">3.14 * 900</gadget>
<output>2_826</output>

<result>2_826</result>