A piece of rope surrounds exactly a rectangle with a length of 20 decimeters and a width of 12 decimeters. If this rope is used to form a square, what is the area of the square in square meters?
一根绳子，恰好围成一个长20分米、宽12分米的长方形，如果用这根绳子围成一个正方形，这个正方形的面积是多少平方米？
<gadget id="calculator">20 + 12</gadget>
<output>32</output>

<gadget id="calculator">32 * 2</gadget>
<output>64</output>

<gadget id="calculator">64 / 4</gadget>
<output>16</output>

<gadget id="calculator">16 * 16</gadget>
<output>256</output>

<result>256</result>