Question

how to get the equation of a right angle bisector line?

Answer 1

Make it into y = mx + b form if you like

What is the slope of the perpendicular line?

You can then find the angle bisector as the 45 degree line.

Answer 2

If you choose appropriate directions, the angle between a vector on ax+by+c=0 (you know what this looks like) and another vector on the bisector should be 45 degrees. Note that the length of the vectors doesn’t matter here. Using dot product you can solve for the vector on the bisector, which determines the direction of the bisector. Find a point on the bisector and use it to write a parametric equation for the bisector. Transform that to normal equation.

Answer 3

When to use the positive value or negative value?