A rectangle with a length of 9 cm and a width of 5 cm, after cutting out the largest square, what is the area of the remaining figure in square centimeters?
一个长9厘米，宽5厘米的长方形，剪下一个最大的正方形后，剩下的图形的面积是多少平方厘米．
<gadget id="calculator">9 * 5</gadget>
<output>45</output>

<gadget id="calculator">5 * 5</gadget>
<output>25</output>

<gadget id="calculator">45 - 25</gadget>
<output>20</output>

<result>20</result>