Crossword Objective Terms/Dictionary Conga Line

Window Pane TERM Picture Like Definition Useful example

Undefined Terms Points, Lines, & Planes The principal concepts foundations of any Euclidean geometry. Points, Lines, & Planes

Postulates The underlying assumptions in a geometric system. Do not require a proof and presumed to be true.

Theorems Are statements that require a proof to be true.

Point a location in space represented by a dot Point A A Point Y Y

Line A series of points that are extended infinitely in opposite directions AB or BA line m A B m

Line Segment A part of a line with two points, called endpoints, and all points between them PQ or QP P Q

Ray Part of a line consisting of one endpoint and all the points of the line on one side of the endpoint TV T V

Plane A flat surface extending infinitely in all directions. ***Any 3 non-collinear pts. always form a plane X B A C Plane X Plane ABC

Collinear points Points that lie on the same line T V U W

Non-collinear points Three or more points that do not lie on the same line T V U W

Coplanar Points that lie in the same plane; lines that lie in the same plane X B A C

Non-coplanar Four or more points that do not lie in the same plane; lines that do not lie in the same plane

Opposite rays Two rays with a common endpoint which form a line

Intersecting lines Lines that meet at a single point

Parallel Lines Coplanar lines that do not intersect MN // OP

Perpendicular Lines Lines that meet to form 90° angles SQ ┴ PR

Skew Lines Non-coplanar lines that do not intersect AB is skew to EF

Congruent Objects of the same shape and size

Congruent segments Segments of the same length EF HG

Midpoint A point that divides a segments into two congruent segments PM MQ, M is the midpoint

Segment Bisector Segment, line, or ray that passes though the midpoint of a segment

Angle Formed by two rays with common endpoint <ABC or <B