Ch 1 Flashcards
Indicates a position
POINT
A straight path extending infinitely in opposite directions. One-dimensional.
LINE
Part of a line with two endpoints.
LINE SEGMENT
Part of a line that starts at a point and extends infinitely in one direction.
RAY
Lines that are always the same distance apart. They never meet.
PARALLEL LINES
Lines that intersect to form four right angles (angles that measure 90°).
PERPENDICULAR LINES
The point of intersection of two or more line segments, rays, or lines.
VERTEX
Formed by two rays with the same endpoint, the vertex.
ANGLE
A shape with three sides, three angles, and three vertices.
TRIANGLE
Line segments that have the same lengths.
CONGRUENT LINE SEGMENTS
The halfway point of a line segment. It divides the line segment into two congruent segments.
MIDPOINT
A flat surface that extends infinitely in all directions.
PLANE
A line, ray, segment, or plane that passes through a segment at its midpoint (bisects it).
SEGMENT BISECTOR
Points lie on the same line.
COLLINEAR
The point or line where lines or planes pass through or lie across each other.
INTERSECTION
Points lie on the same plane.
COPLANAR
Logical reasons used to confirm an idea.
PROOFS
Used to support proofs.
POSTULATES, THEOREMS
A statement that is accepted as fact, without proof.
POSTULATE
A statement that has been proven to be true using other theorems, definitions, and/or postulates.
THEOREM
