I make a point of intersection with straight lines as many as possible.
There is one point of intersection at most with two lines and there are three points at most with three lines.
How many points are there at most with eight lines ?
Answer
28 points
Solution
When you increase one straight line, you should draw it so that it makes new point of intersection with straight lines already drawn.
In case of four straight lines you draw, there are 3 + 3 = 6 points of intersection.
In case of five lines, 6 + 4 = 10.
In the case of eight lines then, there are 1 + 2 + 3 + 4 + 5 + 6 + 7 = 28 points.