Bisection

In geometry, bisection is the division of something into two equal parts. This is usually done by a line, which we will call the "bisector". The most known types are the segment bisector (a line that passes through the middle of a given segment) and the angle bisector (a line that passes through the apex of an angle, that divides it into two equal angles.

Not to be confused with Dissection.

For the bisection theorem in measure theory, see Ham sandwich theorem. For the root-finding method, see Bisection method.

In three-dimensional space, bisection is usually done by a plane, which is also called the bisector or bisecting plane.