A rectangular art work is 20 cm wide and its circumference is 112 cm. What is the length of this work in cm?
一副长方形美术作品，宽是20厘米，它的周长是112厘米，这幅作品的长度是多少厘米？
<gadget id="calculator">112 / 2</gadget>
<output>56</output>

<gadget id="calculator">56 - 20</gadget>
<output>36</output>

<result>36</result>