Xiaojun measured the circumference of a tree trunk is 125.6cm, what is the cross-sectional area of the tree trunk in square centimeters?
小军测得一棵树干的周长是125.6cm，则这棵树干的横截面积多少平方厘米．
<gadget id="calculator">3.14 * 400</gadget>
<output>1_256</output>

<result>1_256</result>