There are 8 points on the circumference of the circle, and any two points are connected by a line segment, then how many intersection points do these line segments have at most in the circle.
圆周上有8个点，任意两点用线段连接，那么这些线段在圆内最多有多少个交点．
<gadget id="calculator">8 * 7 * 6 * 5</gadget>
<output>1_680</output>

<gadget id="calculator">4 * 3 * 2 * 1</gadget>
<output>24</output>

<gadget id="calculator">1_680 / 24</gadget>
<output>70</output>

<result>70</result>