If a 280-meter-long iron wire encloses a square, what is the area of the enclosed square?
用一根长280米的铁丝围成一个正方形，那么围成的正方形的面积有多大？
<gadget id="calculator">280 / 4</gadget>
<output>70</output>

<gadget id="calculator">70 * 70</gadget>
<output>4_900</output>

<result>4_900</result>