Cut a rectangle with a length of 20m and a width of 18m into the largest square, what is the cut area in m**2.
将长20m，宽18m的长方形剪成一个最大的正方形，剪去的面积是多少m**2．
<gadget id="calculator">18 * 18</gadget>
<output>324</output>

<result>324</result>