Draw the largest circle inside a square with a circumference of 16 decimeters. What is the area of the circle equal to the area of the square?
在一个周长为16分米的正方形内画一个最大的圆，这个圆的面积是正方形面积的多少．
<gadget id="calculator">16 / 4</gadget>
<output>4</output>

<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<gadget id="calculator">16 / 4 / 16</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">3.14 * (1/4)</gadget>
<output>0.785</output>

<result>0.785</result>