A rectangular iron plate, the width is the length (4/5). Cut off 21 cm from the wide side, cut off a part of the long side, keep 65% of the original length, and get a square iron plate. What is the length of the original rectangular iron plate in centimeters?
一块长方形铁板，宽是长的(4/5)．从宽边截去21厘米，长边截去一部分后，保留原长的65%，得到一块正方形铁板．原来长方形铁板的长是多少厘米？
<gadget id="calculator">21 / 0.15</gadget>
<output>140</output>

<result>140</result>