A square with a side length of a meter, if 4 equal and largest circles are cut on this paper, what is the sum of the areas of the four circles?
一张边长为a米的正方形，如果在这张纸上剪4个相等且最大的圆，四个圆的面积和约是这张纸的多少
<gadget id="calculator">3.14 / 4</gadget>
<output>0.785</output>

<result>0.785</result>