Take a 15-meter rope and wrap it around the cylindrical pillar. After 10 turns, there is still 2.44 meters left. How big is the base area of this stone pillar?
拿一根15米的绳子绕在圆柱形台柱上，绕10圈之后还剩2.44米，这根石柱的底座面积有多大？
<gadget id="calculator">15 - 2.44</gadget>
<output>12.56</output>

<gadget id="calculator">12.56 / 10</gadget>
<output>1.256</output>

<gadget id="calculator">1.256 / 3.14 / 2</gadget>
<output>0.2</output>

<gadget id="calculator">0.2 ** 2</gadget>
<output>0.04</output>

<gadget id="calculator">3.14 * 0.04</gadget>
<output>0.1256</output>

<result>0.1256</result>