The diameter of a circle is 10 cm. If its diameter is doubled, what is the radius of the enlarged circle in cm?
一个圆的直径是10cm，如果它的直径扩大为原来的2倍，则扩大后的圆的半径为多少cm
<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<result>10</result>