If there is a rectangle with a length of 70 cm and a width of 50 cm, what is the perimeter of the largest square?
有一个长70厘米、宽50厘米的长方形，如果剪成一个最大的正方形周长是多少？
<gadget id="calculator">50 * 4</gadget>
<output>200</output>

<result>200</result>