wire can form a circle with a radius of 4 cm. If the wire is re-enclosed into a square, what is the side length of the square?
一根铁丝可以围成一个半径是4厘米的圆．如果把这根铁丝重新围成一个正方形，这个正方形的边长是多少？
<gadget id="calculator">4 / 4</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 2 * 1</gadget>
<output>6.28</output>

<result>6.28</result>