On a circle, there are A1A2A3...A1010 points, how many line segments can be drawn in total (with these 10 points as endpoints).
在一个圆周上，有A1A2A3…A1010个点，问一共能画出多少条线段(以这10个点为端点)．
<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<gadget id="calculator">9 / 2</gadget>
<output>9/2 = around 4.5</output>

<gadget id="calculator">10 * (9/2)</gadget>
<output>45</output>

<result>45</result>