A wire 100 cm long forms a square with a side length of 10 cm, and the remaining wires form a rectangle with a width of 10 cm. What is the length of this rectangle in centimeters?
一根铁丝长100厘米，围成一个边长为10厘米的正方形，余下的铁丝围成一个宽为10厘米的长方形．这个长方形的长是多少厘米？
<gadget id="calculator">10 * 4</gadget>
<output>40</output>

<gadget id="calculator">100 - 40</gadget>
<output>60</output>

<gadget id="calculator">60 / 2</gadget>
<output>30</output>

<gadget id="calculator">30 - 10</gadget>
<output>20</output>

<result>20</result>