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90 terms

Eisenberg Vocabulary

includes points, lines, rays, angles, polygons, triangles, quadrilaterals, circles
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point
has no size, only location
line
straight, continous arrangement of infinitely many points; has no thickness; one-dimensional
plane
flat surface; two-dimensional; surface extends indinitely along its length and width; a plane is named with script capital letter
collinear
points that lie along the same line
coplainar
points that lie within the same plane
line segment
consists of two points called the endpoints of the segment and all the points between them that are collinear with the two points
congruent segments
segments that are equal in measure or length
midpoint
the point on the segment that is the same distance from both endpoints. A pair of hatch marks refer to line segments being the same length
bisects-
to cut in half
ray
begins at a point and extends infinitely in one direction
angle
formed by two rays that share a common endpoint
vertex
the common endpoint of the two rays of the angle
sides
the rays of an angle
measure of an angle
the smallest amount of rotation about the vertex from one ray to the other
degrees
unit of measurement for an angle
protractor
a geometry tool used to measure angles
congruent angles-
angles that are equal in measure
angle bisector
a ray that divides the angle into two congruent angles
parallel lines
lines that do not intersect and are part of the same plane
perpendicular lines
lines that do intersect and form a right angle
skew lines
lines that are neither parallel nor do they intersect (for 3-D setting)
right angle
an angle that measures 90 degrees
acute angle
an angle that measures less than 90 degrees
obtuse angle
an angle that measures more that 90 degrees
pair of vertical angles
angles that are formed by two intersecting lines; they share a common vertex but not a common side
linear pair of angles
two angles are a ____if they share a vertex and a common side and their non-common sides form a line
complementary angles
angles that form a right angle
supplementary angles
angles that sum up to 180 degrees
polygon
closed figure in a plane, formed by connecting line segments endpoint to endpoint with each segment intersecting the other
consecutive vertices
vertices that are adjacent to one another
consecutive angles
angles that are adjacent to one another
diangonal
a line segment that connects any two nonconsecutive vertices
concave polygon
a polygon that has at least one diagonal on the outside
convex polygon
a polygon that has no diagonals on the outside
congruent polygons
polygons that have exactly the same size and shape
equilateral polygons
a polygon who's sides are all equal
equilangular polygon
a polygon whose angles are all equal
regular polygon
a polygon whose sides and angles are all equal
triangle
3 sides
quadrilateral
4 sides
pentagon
5 sides
hexagon
6 sides
heptagon
7 sides
octagon
8 sides
nonagon
9 sides
decagon
10 sides
enneagon
11 sides
dodecagon
12 sides
triskaidecagon
13 sides
tetrakaidecagon
14 sides
pentakaidecagon
15 sides
hexakaidecagon
16 sides
heptakaidecagon
17 sides
octakaidecagon
18 sides
nonakaidecagon
19 sides
icosagon
20 sides
icosakaihenadecagon
21 sides
triacontagon
30 sides
hectagon
100 sides
chiliagon
1000 sides (chilagon?)
myriagon
10000 sides
acute triangle
all angles are less than 90 degrees
obtuse triangle
one angle is more than 90 degrees and less than 180 degrees of a three sided polygon
right triangle
one angle is exactly 90 degrees
scalene triangle
no two sides are congruent of a three sided polygon
isosceles triangle
at least two sides are congruent of a three sided polygon
equilateral triangle
all sides are congruent of a three sided polygon
trapazoid
a quadrilateral with exactly one pair of parallel sides
isosceles trapazoid
top and bottom are parallel, two sides are congruent, top two angles are congruent, bottom two angles are congruent
right trapazoid
two right angles
kite
a quadrilateral with two pairs of consecutive congruent sides. The diagonails are perpendicular
parallelogram
a quadrilateral with two pairs of parallel sides
rhombus
an equilateral parallelogram
rectangle
a parallelogram with four congruent angles (right angles); an equilateral parallelogram
square
an equilateral, equilangular parallelogram; a regular quadrilateral; an equalateral rectangle
circle
a set of all points in a plane that are the same distance from a given point (center) in a plane
radius
a line segment from the center point of a circle to a point on the edge of a circle
diameter
a line segment passing through the center point of a circle and whose endpoints are on the edge of the circle
chord
any line segment whose endpoints are on the edge of a circle; the diameter is the longest chord
congruent circles
circles that have the same radius length
concentric circles
circles that share the same center point
arc of a circle
the continuous (unbroken) part of a circle that is in between two points on the edge of a circle
semicircle
arc of a circle whose endpoints are the endpoints of the diameter
minor arc
an arc of a circle that is smaller than a semicircle
major arc
an arc of a circle that is larger than a semicircle
arc measure
the measure of the central angle (in degrees)
central angle
angle formed by two radii and whose vertex is the center point of a circle
tangent
a line that intersects the circle at exactly one point
secant
a line that intersects the circle at exactly two points
inscribe angle
angle whose vertex is the point on a circle; the sides of this angle are the chords of the circle