Download 1.) Point: A location in space (no size) 2.) Line: a series of points that

GEOMETRY VOCABULARY
1.) Point: A location in space (no size)
2.) Line: a series of points that extend in two opposite
directions (never ends)
3.) Plane: flat surface, no thickness
4.) Segment: part of a line consisting of two points, called
endpoints
5.) Length of a Segment: the distance from A to B
6.) Collinear: points that are on the same line
7.) Non-Collinear: points that are NOT on the same line
8.) Coplanar: points and lines that are in the same plane
9.) Finite: has an end; stops (opposite of infinite)
10.) Circle: the set of all points in a plane r distance
from point C
11.) Diameter: the distance across a circle through its center
12.) Radius: a segment from the center of a circle to a point
on the circle. It is ½ the diameter; all radii have
the same length
13.) Figure: set of points in a plane (refers to shapes)
14.) Geometric Construction: a set of instructions for drawing
points, lines, circles, and figures
15.) Equilateral Triangle: a triangle in which all 3 sides are the
same length
16.) Regular Hexagon: a six sided polygon where all sides and
all interior angles are the same measure
17.) Ray: a portion of a line that has one endpoint and
extends infinitely in the other direction
18.) Angle: a figure formed by two rays with a common
endpoint called a vertex
19.) Vertex: the common endpoint of two or more rays or line
segments
20.) Interior of an Angle: the ‘inside’ of an angle
21.) Exterior of an Angle: the ‘outside of an angle
22.) Angle Bisector: a ray that divides an angle into two equal
(congruent) angles
23.) Degree: a unit of angle measure
24.) Zero Angle: a ray that measures 0o
25.) Straight Angle: a ray that measures 180o
26.) Right Angle: an angle that measures 90o
27.) Equidistant: the same distance
28.) Midpoint: the point that is exactly halfway between two
other points; it divides a line segment into two
congruent segments.
29.) Perpendicular: two lines that intersect to form right angles
30.) Perpendicular Bisector: a line that passes through the
midpoint and forms a right angle
with a segment
31.) Concurrent: A set of lines that all intersect at the same
point is said to be concurrent
32.) Point of Concurrency: the point of intersection of
concurrent lines
33.) Circumcenter: the point of concurrency for the three
perpendicular bisectors of a triangle
34.) Incenter: the point of concurrency for the three angle
bisectors of a triangle
35.) Median: the line that connects a vertex of a triangle to
the midpoint on the corresponding side
36.) Centroid: the point of concurrency for the three medians
of a triangle
37.) Altitude: the perpendicular line that goes from the vertex
of a triangle to the corresponding side
38.) Orthocenter: the point of concurrency for the three
altitudes of a triangle
39.) Centroid Theorem: states that the centroid of a triangle is
located
of the way from each
vertex to the midpoint of the
corresponding side