What is the width of a rectangle with a length of 8 cm and a circumference of 20 cm?
长8厘米，周长20厘米的长方形，它的宽是多少厘米
<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">10 - 8</gadget>
<output>2</output>

<result>2</result>