Xiao Ming cuts out the largest circle on a rectangular piece of paper with a length of 30 cm and a width of 18 cm. What is the remaining area in square centimeters?
小明在一张长30厘米，宽18厘米的长方形纸片上，剪下一个最大的圆，剩下的面积是多少平方厘米？
<gadget id="calculator">30 * 18</gadget>
<output>540</output>

<gadget id="calculator">18 / 2</gadget>
<output>9</output>

<gadget id="calculator">9 ** 2</gadget>
<output>81</output>

<gadget id="calculator">3.14 * 81</gadget>
<output>254.34</output>

<gadget id="calculator">540 - 254.34</gadget>
<output>285.66</output>

<result>285.66</result>