There is a circular iron plate with a square cut out in the middle. The area of the square is 5 square centimeters. The radius of the circle is exactly the length of the diagonal of the square. How many square centimeters is the area of the circle larger than the area of the square?
有一个圆形铁片，中间挖去一个正方形，正方形的面积是5平方厘米，圆的半径恰好是正方形的对角线长，圆面积比正方形面积大多少平方厘米．
<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">3.14 * (5/2)</gadget>
<output>7.85</output>

<gadget id="calculator">7.85 - 5</gadget>
<output>2.85</output>

<result>2.85</result>