Intersection point between two lines (boundary points given) after extrapolating ?

Two lines with boundary points are given . i need to find intersection point between these lines (after extrapolating them ) without the use of skope and intercept

[Jan]

What does "extrapolating them" mean? What is "skope" and "intercept"?

[Nitin Sehra]

[Nitin Sehra]

the other point on red line is (100,107.5).these two lines are not intersecting unless extrapolated...i need the function for intersection point using only these 4 points.

[Matt J]

What do you mean when you say you can't use slope and intercept? What prevents you from doing that? For a general pair of lines, there is no way to compute their intersection without deriving the equations for the lines.

Answer 1

[Matt J]

You might think this avoids slope and intercept, but it doesn't.

p1=[100;107.5;1];
p2=[100;17.5;1];

p3=[12.5;110;1];
p4=[102.5;110;1];

P=cross(  cross(p1,p2)   , cross(p3,p4)  );

P=P(1:2)/P(3) %intersection point

P = 2×1

100 110