There are 10 points on the plane, and there is no case where three points lie on a straight line. How many line segments can these points be connected to?
平面上有10个点，没有三点在一直线上的情况．这些点可以连成多少条线段．
<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>