Constructions and loci

With the compass centered at A, draw arcs above and below AB. Repeat with the compass centered at B, ensuring the arcs intersect. Draw a straight line through the intersection points; this is the perpendicular bisector.

Place the compass at vertex B and draw an arc intersecting BA and BC. From these intersection points, draw two arcs that intersect. Draw a line from B to the intersection point of the arcs. This line bisects the angle ABC.

The locus of points equidistant from a fixed point is a circle. The fixed point is the center of the circle, and the distance represents the radius.

The locus of points equidistant from two points A and B is the perpendicular bisector of the line segment AB. Every point on the perpendicular bisector is the same distance from A and B.

The locus of points equidistant from two intersecting lines is a pair of angle bisectors of the angles formed by the intersecting lines. Any point on these bisectors is equidistant from both lines.

A protractor measures angles directly. Construction uses a compass and ruler to create angles based on geometric principles for accuracy.

Draw a straight line. With the compass centered at one endpoint, draw an arc. Keeping the same compass width, place the compass at the intersection of the arc and the line, and draw another arc intersecting the first. Draw a line from the endpoint to this intersection.