Rotate a square along the straight line where one of its sides is located to obtain a cylinder with a base circumference of 25.12 cm. What is the area of this square in square centimeters?
把一个正方形沿着它们的一条边所在的直线旋转一周，得到一个底面周长为25.12厘米的圆柱，这个正方形的面积是多少平方厘米．
<gadget id="calculator">25.12 / 3.14 / 2</gadget>
<output>4</output>

<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<result>16</result>