A bisector.
It is a line of symmetry.
bisector
A line segment that divides a circle in two is a chord.If the two parts of the circle are equal, the line segment is a diameter.See 'The Parts of the Circle' in Sources and related links, below.
The midpoint.
When a line divides another in two equal parts, it is called a bisector. If the bisector happens to cross the other line at right angles, it is called a perpendicular bisector.
the middle of something divides it into two equal parts not the center because the center divides it into 4 equal parts
90 degree bisector
Lake Michigan divides Michigan into two parts
The midpoint or bisector divides a segment into two congruent parts.
The midpoint divides a line segment into congruent parts.
The equator.
A chord is a straight line within a circle that divides the circle into two parts - these parts are called arcs.The diameter is a chord that runs through the centre of the circle and divides the circle into two equal parts.
The equator is the parallel that divides the Earth into two equal parts: the Northern Hemisphere and the Southern Hemisphere. It is an imaginary line situated halfway between the North Pole and the South Pole.
Divider
diameter
prime meridean