Cut a circular piece of paper into two equal semicircles, and its circumference increases by 10cm. What is the area of the circle in cm**2.
把一个圆形纸片剪成两个相等的半圆，它的周长增加了10cm，这个圆的面积是多少cm**2．
<gadget id="calculator">10 / 2 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">(5/2) ** 2</gadget>
<output>25/4 = around 6.25</output>

<gadget id="calculator">3.14 * (25/4)</gadget>
<output>19.625</output>

<result>19.625</result>