If the square frame with a circumference of 72 cm is stretched into a parallelogram frame with a height of 15 cm, how much is the area reduced?
把周长是72厘米的正方形框架，拉成高是15厘米的平行四边形框架，面积比原来减少了多少？
<gadget id="calculator">72 / 4</gadget>
<output>18</output>

<gadget id="calculator">18 * 18</gadget>
<output>324</output>

<gadget id="calculator">18 * 15</gadget>
<output>270</output>

<gadget id="calculator">324 - 270</gadget>
<output>54</output>

<result>54</result>