Drawing of bissectrisa.

[shaman4d]

How I can draw the blue line?

[realMakc]

if you have normals of A and B pointing to one direction, then blue line direction will be (n(A) + n(B))/2

[shaman4d]

if you have normals of A and B pointing to one direction, then blue line direction will be (n(A) + n(B))/2

How I can determine normals direction relative one another?

[realMakc]

On the 2nd thought, you can also do this with direction vectors themselves. Assuming you know some two points on A and B, you have d(A) = (A - O)/|A - O| and d(B) = (B - O)/|B - O|, then d(C) = (d(A) + d(B)) / |d(A) + d(B)|

[shaman4d]

On the 2nd thought, you can also do this with direction vectors themselves. Assuming you know some two points on A and B, you have d(A) = (A - O)/|A - O| and d(B) = (B - O)/|B - O|, then d(C) = (d(A) + d(B)) / |d(A) + d(B)|

I dont understand mean the d(C) - what is it?

[realMakc]

direction vector of line C