The trunk circumference of a large tree is 125.6 cm, what is the cross-sectional area of this large tree?
一棵大树的树干周长是125.6厘米，这棵大树的横截面积是多少？
<gadget id="calculator">125.6 / 2 / 3.14</gadget>
<output>20</output>

<gadget id="calculator">20 ** 2</gadget>
<output>400</output>

<gadget id="calculator">3.14 * 400</gadget>
<output>1_256</output>

<result>1_256</result>