A long line segment has 11 points including the two endpoints. How many line segments does it include? Given that the distance between two adjacent points is 1 cm, what is the sum of the lengths of all line segments?
一个长线段包括两个端点在内共有11个点．他包括多少条线段？已知相邻两点的距离都是1厘米，那么所有线段的长度总和是多少．
<gadget id="calculator">11 - 1</gadget>
<output>10</output>

<gadget id="calculator">1 * 10</gadget>
<output>10</output>

<gadget id="calculator">2 * 9</gadget>
<output>18</output>

<gadget id="calculator">3 * 8</gadget>
<output>24</output>

<gadget id="calculator">4 * 7</gadget>
<output>28</output>

<gadget id="calculator">5 * 6</gadget>
<output>30</output>

<gadget id="calculator">6 * 5</gadget>
<output>30</output>

<gadget id="calculator">7 * 4</gadget>
<output>28</output>

<gadget id="calculator">8 * 3</gadget>
<output>24</output>

<gadget id="calculator">9 * 2</gadget>
<output>18</output>

<gadget id="calculator">10 * 1</gadget>
<output>10</output>

<gadget id="calculator">10 + 18 + 24 + 28 + 30 + 30 + 28 + 24 + 18 + 10</gadget>
<output>220</output>

<result>220</result>