If the circumference of a square is equal to that of a circle with a radius of 10 cm, what is the area of the square?
一个正方形与一个半径为10cm的圆的周长相等，正方形的面积是多少．
<gadget id="calculator">3.14 * 10 * 2</gadget>
<output>62.8</output>

<gadget id="calculator">62.8 / 4</gadget>
<output>15.7</output>

<gadget id="calculator">15.7 * 15.7</gadget>
<output>246.49</output>

<result>246.49</result>