The height of a cylindrical biscuit box is 15.7 cm, and its side wrapping paper is unfolded to form a square. What is the area of the bottom of the biscuit box in square centimeters?
一个圆柱形饼干盒高是15.7厘米，把它的侧面包装纸展开是一个正方形，这个饼干盒的底面积是多少平方厘米．
<gadget id="calculator">15.7 / 3.14 / 2</gadget>
<output>2.5</output>

<gadget id="calculator">2.5 ** 2</gadget>
<output>6.25</output>

<gadget id="calculator">3.14 * 6.25</gadget>
<output>19.625</output>

<result>19.625</result>