definitions and symbols © 2008 mr. brewer. a flat surface that never ends

Definitions and Symbols

© 2008 Mr. Brewer

A flat surface that A flat surface that never endsnever ends

An exact locationAn exact location

. ARead - point A Write

- A

A straight figure with A straight figure with two endpoints.two endpoints.

ABWrite

Read – line segment ab

a b

A straight figure with no A straight figure with no endpoints and goes on endpoints and goes on

forever in both directionsforever in both directions..

GH

Write -

Read – line GH

G H

A straight figure with one end A straight figure with one end point. It goes on forever in point. It goes on forever in

one directionone directionB A

BA

Write

Read – ray BA

An angle is formed by two An angle is formed by two rays with the same endpointrays with the same endpoint

QR

P Read – angle PQR or angle RQP or

angle QWrite -

PQRQ RQP

A common endpoint of A common endpoint of two rays or line two rays or line

segments.segments.

vertex

When the two sides of an When the two sides of an angle form a square corner. angle form a square corner.

The angle measures 90The angle measures 9000..

An angle that measures An angle that measures less than 90less than 9000..

Angle Angle measures measures less than less than

909000

An angle that measures An angle that measures more than 90more than 9000..

Angle Angle measures measures more than more than

909000

Lines that meet or Lines that meet or cross at a common cross at a common

pointpoint

AB and

Write -

CD intersect at point E

A D

C BE

Intersecting lines that Intersecting lines that form right angles.form right angles.

FIH

G

J

Read – line FG is perpendicular to line HI

HI

Write -

FG

Lines in the same Lines in the same plane that never crossplane that never cross

Read – line KL is parallel to line MN

M N

K L

KLWrite -

KL

A plane figure where all the points on the A plane figure where all the points on the circle are the same distance from the circle are the same distance from the center. A circle is named by its center center. A circle is named by its center

pointpoint

. A Circle A

A point in the center A point in the center of a circleof a circle..

Center

Any line segment with endpoints Any line segment with endpoints at the center of the circle and on at the center of the circle and on

the circle.the circle.

BCBC is a radiusof circle BB

CB

Any line segment that passes through the Any line segment that passes through the center of the circle and has both endpoints center of the circle and has both endpoints

on the circle. Twice the length of the radius.on the circle. Twice the length of the radius.

CDCD is a diameterof circle BBC

D

B

A path that begins and ends at A path that begins and ends at the same point and does not the same point and does not

cross itself cross itself

A closed figure formed from line segments that do not A closed figure formed from line segments that do not cross. Polygon means, “Many Angles.” Most polygons are cross. Polygon means, “Many Angles.” Most polygons are

named for the number of angles it has.named for the number of angles it has.Ex. Tri means 3… TriangleEx. Tri means 3… Triangle

““Must have 3 or more sides.”Must have 3 or more sides.”

A four sided polygonA four sided polygon

A quadrilateral with opposite A quadrilateral with opposite sides that are parallel and the sides that are parallel and the

same lengthsame length14

in.

14 in

.

8 in.

8 in.

AA quadrilateral with opposite sides quadrilateral with opposite sides that are parallel, the same that are parallel, the same

length, and have all right angleslength, and have all right angles

10 in

All Right Angles4

in

4 in

10 in

A quadrilateral with opposite sides that A quadrilateral with opposite sides that are parallel, all the sides are the same are parallel, all the sides are the same

length, and have all right angleslength, and have all right angles

All Right Angles

4 in

4 in

4 in

4 in

A parallelogram with A parallelogram with all four sides equalall four sides equal

22 in

22 in

22 in

22 in

A quadrilateral with exactly A quadrilateral with exactly one pair of parallel sidesone pair of parallel sides

Parallel

Sides

A polygon with three A polygon with three sidessides

A triangle with one A triangle with one right angle.right angle.

A triangle whose sides A triangle whose sides are all equal in lengthare all equal in length

8 mm

8 m

m

8 mm

None of the sides are None of the sides are equal in lengthequal in length

12 in

40 in

34 in

Two sides are equal Two sides are equal in lengthin length

20 cm

20 c

m

15 cm

Figures with exactly the same Figures with exactly the same shape. They may or may not be shape. They may or may not be

the same sizethe same size

Figures with exactly the Figures with exactly the same size and shape. same size and shape.

Movement of a figure Movement of a figure along a line. along a line.

A movement of a figure over a line so A movement of a figure over a line so that the figure faces in the opposite that the figure faces in the opposite

direction. The lines may be imaginarydirection. The lines may be imaginary..

The movement of a The movement of a figure around a point.figure around a point.

90 degree turn 180

degree turn

The movement of a The movement of a figure around a point.figure around a point.

270 degree turn 360

degree turn

A figure has a line of symmetry if it can be A figure has a line of symmetry if it can be folded so that its two parts match. The folded so that its two parts match. The

fold is called the line of symmetry. fold is called the line of symmetry.

A pair of numbers used to locate a point on a A pair of numbers used to locate a point on a grid. The first number tell you to move grid. The first number tell you to move

across the across the X – axisX – axis. The second number tells . The second number tells you to move up or down the you to move up or down the Y – axis.Y – axis.

3 , 2Says move 3 right

Move 2 up to your pointX

Y

The starting point or the The starting point or the

ordered pair (ordered pair (0 , 00 , 0))

X

Y origin

A figure that has one or A figure that has one or more lines of symmetry. more lines of symmetry.