4 small squares with a side length of 5 cm are used to form a rectangle. What is the perimeter of the rectangle in cm?
用4个边长是5厘米的小正方形拼成一个长方形，长方形的周长是多少厘米．
<gadget id="calculator">25 * 2</gadget>
<output>50</output>

<result>50</result>