Geometry: Points, Lines, Angles, and Polygons

A set of vocabulary flashcards defining fundamental geometric concepts, types of lines, and point relationships based on the Chapter 9.1 lecture notes.

Point

An exact location on a 2D plane or specific position in space ($3D$) that has no definite size, magnitude, or dimensions ($0-D$).

Line

A collection of points that extends infinitely in opposite directions.

One-dimensional ($1-D$) figures

Figures that have length or breadth only and consist of a collection or set of points.

Open shapes

Figures where the two end-points of lines never meet, such as lines and angles.

Spiral

A coiled line.

Bisecting lines

Lines that half each other.

Parallel lines

Sets of lines that are the same distance apart all over and never meet.

Perpendicular lines

Lines that intersect at $90^{\circ}$ or right angles.

Intersecting lines

Lines that meet at at least one point.

Angles

Geometric structures formed where two or more lines meet at a point.

Collinear points

When 2 or more points lie on the same line.

Non-collinear points

Points in a figure that do not lie on the same line.

Concurrent lines

A set of lines that intersect at a single common point.

Transversal

A line that intersects two or more distinct lines at different points.

Congruent lines

Line segments that have the same length, written as $AB \cong CD$ if $AB = CD$.

Midpoint

The point on a line segment that is the same distance from $A$ to $B$.

X-coordinate

The distance moved from the origin to spaces to the right on a coordinate grid.

Y-coordinate

The distance moved five spaces upward from the x-coordinate on a coordinate grid.