To draw a circle with a diameter of 2.8 cm, what is the distance in cm between the legs of the compass?
要画一个直径是2.8cm的圆，圆规的两脚张开的距离是多少cm．
<gadget id="calculator">2.8 / 2</gadget>
<output>1.4</output>

<result>1.4</result>