1Perpendicular bisector
Every point on the perpendicular bisector of AB is the same distance from A and B.
2Angle bisector
Every point on an angle bisector is equally distant from the two arms of the angle.
3Common loci
- Fixed distance from a point: a circle.
- Fixed distance from a line: two parallel lines.
- Equidistant from two points: a perpendicular bisector.
4Construct accurately
Keep compass arcs visible and use equal radii where required. Do not replace construction marks with measurement.
💡Region questions: draw every boundary first, then shade only the overlap satisfying all conditions.