A circle is formed by a 41.4 cm long iron wire (0.1 meters in total at the joints), what is the radius of this circle?
用一根长41.4厘米的铁丝围成一个圆(接头处共0.1米)，这个圆的半径是多少．
<gadget id="calculator">0.1 * 100</gadget>
<output>10</output>

<gadget id="calculator">41.4 - 10</gadget>
<output>31.4</output>

<gadget id="calculator">31.4 / 3.14 / 2</gadget>
<output>5</output>

<result>5</result>