Vertex

the point where two lines, line segments, or rays meet to form an angle Point A is a vertex for the angles formed.

A

sequenceA set of numbers arranged in a certain

order or pattern

2, 4, 6, 8, 10

3, 6, 3, 9, 3, 12

measure of an arc

The degree measure of an arc is equal to the measure of its central angle.

0

0

75

75

m ACB

mAB

C

BA

Rhombus

Quadrilateral with four equal sides

Diagonal

Line segment that joins two vertices of a polygon, but is not a side of the polygon

Diagonals

bisect

To divide into two equal parts, cut in halfGI bisects FGH

means that

m FGI = m HGI

C

A B

D

EG

F

H

I

DE bisects AB

means that

C is the midpoint of AB

and AC=CB

GI bisects FGH

means that

m FGI = m HGI

apothem

Segment from the center of a polygon perpendicular to the side of the polygon

apothem

Central angle

Angle in a circle with its vertex at the center of the circle

B

CA

ABC is a central angle.

Vertical angles The opposite angles formed when two

lines intersect

1 432

1 and 3 are vertical angles.

2 and 4 are vertical angles.

Vertical angles are congruent.

reciprocals

Two numbers that have a product of 1

2 3 and are reciprocals

3 22 3

= 13 2

15 and are reciprocals

51

5 = 15

13 and are reciprocals

31

3 = 13

edge

Line segment where two faces of a solid figure meet

edge

face

Plane figure that serves as one side of a solid figure

face

polygon

A closed figure formed from line segments that meet only at their endpoints

Perpendicular lines

Two lines that intersect and form a right angle

A CE

B

D

AC BD

BEC is a

right angle.

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Prime notation

When figures are transformed, prime notation is often used to name the image.

The point P’ (read P prime) is the image of point P

B'

A'

C'

B

A

C

8

7

6

5

4

3

2

1

-1

-2

-3

-4

-5

-6

2 3 4 5 6 7 8-1-2-3-4-5-6-7-8 1

Reflect DABC across the x-axisDABC DA’B’C’

x

y

Tesselation

Repeating pattern of figures that fills a plane completely

No overlapping of figures, no gap between figures

Tangent to a circle

Line that intersects the circle in exactly one

pointIs perpendicular to the radius of the circle at the point of intersection, called point of tangency

B

A

D

AD is tangent to circle B

at point A.

AD AB point A.

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Quadratic formula

Used to find the solution to a quadratic equation in standard form

x2 + bx + c = 0

2 4 =

2

b b acx

a

Favorable event or outcome

In probability the outcome your are interested in measuring

Example: Rolling two dice and getting a one on each die.

Perpendicular bisector

Line, line segment, or ray that is perpendicular to a line segment at

its midpoint

BA C

D

E

Line DE is perpendicular to segment AC at midpoint B.

DE is the perpendicular bisector of segment AC.

cone

Three dimensional figure with one vertex and one circular base

Vertex

Base

Conditional statement

Statement in the form of If ___, then ___.

If an angle is a right angle, then its measure is 90o.

If a triangle is a right triangle, then it has a right angle.

transversal

A line that intersects two or more linestransversal

secant of a circle

A line that intersects a circle in two points

B

AC AB is a secant of

circle C.

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Regular polygon

Polygon that is equiangular (all angles are equal) and equilateral (all sides

are equalRegular quadrilateral

(square)

Regular triangle,(equilateral and equiangular)

Regular pentagon

Regular hexagon