A square has a quarter circle inside it. Given that the area of the square is 10 square centimeters, what is the area of the quarter circle?
一个正方形的内部有一个四分之一圆．已知正方形的面积是10平方厘米，这个四分之一圆的面积是多少．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">3.14 * 10 * (1/4)</gadget>
<output>7.85</output>

<result>7.85</result>