Section 1.4 – Geometry Using Paper Folding

Perpendicular lines – two lines that intersect to form a right angle

Parallel lines – two coplanar lines that do not intersect

Conjecture – a statement that you think is true. An “educated guess” based on observations.

Postulate: If 2 coplanar lines are perpendicular to the same line, then the lines are parallel.

The distance from a point to a line is the length of the perpendicular segment from the point to the line.

Segment bisector is a line that divides a segment into two congruent parts.

The point where a bisector intersects a segment is the midpoint of the segment.

A bisector that is perpendicular to a segment is called a perpendicular bisector.

An angle bisector is a line or ray that divides an angle into two congruent angles.

Postulate: The distances from a point on the perpendicular bisector to the endpoints of the segment are equal.

Postulate: The distances from a point on the angle bisector to the sides of the angle are equal.