A rectangle with a length of 10 cm and a width of 5 cm is obtained by shortening its length by 2 cm. By how many centimeters is the perimeter of the new rectangle less than the original
一个长10厘米，宽5厘米的长方形，把它的长缩短2厘米后得到一个新的长方形．新长方形的周长比原来少多少厘米
<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<result>4</result>