What is the area of a square welded with 60 decimeters of iron wire?
用60分米的铁丝焊成一个正方形，它的面积是多少．
<gadget id="calculator">60 / 4</gadget>
<output>15</output>

<gadget id="calculator">15 * 15</gadget>
<output>225</output>

<result>225</result>