Draw the largest circle in a rectangle with a length of 10 cm and a width of 5 cm. What is its radius in cm?
在一个长10cm，宽5cm的长方形中画一个最大的圆，它的半径是多少cm．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">5 * (1/2)</gadget>
<output>5/2 = around 2.5</output>

<result>5/2 = around 2.5</result>