There are 10 points on a plane, of which no 3 points lie on a straight line, how many different straight lines can be determined from these points?
平面上有10个点，其中无3个点在一直线上，这些点可以确定多少条不同的直线？
<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>