After enclosing the same piece of iron wire into a square, and then enclosing a circle, it is found that according to the area formula, the ratio of the areas of the two is 4:5, so when calculating the area of a circle, what is pi=?
把同一段铁丝围成一个正方形后，又改围一个圆形，发现按照面积公式得出二者面积之比为4：5，那么在计算圆面积时，圆周率π=多少．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/4) * (1/4)</gadget>
<output>1/16 = around 0.0625</output>

<gadget id="calculator">(1/16) * 5</gadget>
<output>5/16 = around 0.3125</output>

<gadget id="calculator">1 / (5/16)</gadget>
<output>16/5 = around 3.2</output>

<result>16/5 = around 3.2</result>