Draw a circle as large as possible on a piece of rectangular paper with a length of 6 cm and a width of 4 cm. What is the radius of this circle in cm?
在一张长6厘米，宽4厘米的长方形纸上画一个尽可能大的圆，这个圆的半径是多少厘米．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<result>2</result>