Transcript PPT - MrBrewersKids.com

Definitions and Symbols
© 2008 Mr. Brewer
A flat surface that
never ends
An exact location
.A
Read - point A
Write - A
A straight figure with two
endpoints.
a
b
Read – line segment ab
Write
AB
A straight figure with no endpoints
and goes on forever in both
directions.
G
H
Read – line GH
Write -
GH
A straight figure with one end point.
It goes on forever in one direction
B
Read – ray BA
A
Write
BA
An angle is formed by two rays
with the same endpoint
Read – angle PQR or
angle RQP or angle Q
P
Write Q
R
Q
PQR
RQP
A common endpoint of two
rays or line segments.
vertex
When the two sides of an angle
form a square corner. The angle
measures 900.
An angle that measures
less than 900.
Angle
measures
less than 900
An angle that measures
0
more than 90 .
Angle
measures
more than
900
Lines that meet or cross at a
common point
A
D
E
C
Write -
AB
and
B
CD intersect at point E
Intersecting lines that form
right angles.
H
F
J
I
G
Read – line FG is
perpendicular to
line HI
Write FG
HI
Lines in the same plane that
never cross
K
L
M
N
Read – line KL is parallel to line MN
Write -
KL
KL
A plane figure where all the points on
the circle are the same distance from
the center. A circle is named by its
center point
.A
Circle A
A point in the center of
a circle
.
Center
Any line segment with endpoints
at the center of the circle and on
the circle.
C
B
BC is a radius
of circle B
Any line segment that passes through the
center of the circle and has both
endpoints on the circle. Twice the length
of the radius.
C
B
CD is a diameter
of circle B
D
A path that begins and ends
at the same point and does
not cross itself
A closed figure formed from line
segments that do not cross. Polygon
means, “Many Angles.” Most
polygons are named for the number
of angles it has.
Ex. Tri means 3… Triangle
“Must have 3 or more sides.”
A four sided polygon
A quadrilateral with opposite sides
that are parallel and the same length
8 in.
8 in.
A quadrilateral with opposite
sides that are parallel, the
same length, and have all
right angles
All Right
Angles
10 in
4 in
4
in
10 in
A quadrilateral with opposite
sides that are parallel, all the
sides are the same length,
and have all right angles
All Right
Angles
4 in
4 in
4 in
4 in
A parallelogram with
all four sides equal
22 in
22 in
A quadrilateral with exactly
one pair of parallel sides
Parallel
Sides
A polygon with three
sides
A triangle with one
right angle.
A triangle whose sides
are all equal in length
8 mm
None of the sides are equal
in length
40 in
Two sides are equal
in length
15 cm
Figures with exactly the same
shape. They may or may not
be the same size
Figures with exactly the same
size and shape.
Movement of a figure along a
line.
A movement of a figure over a line
so that the figure faces in the
opposite direction. The lines may
be imaginary.
The movement of a figure
around a point.
90
degree turn
180
degree turn
The movement of a figure
around a point.
270
degree turn
360
degree turn
A figure has a line of symmetry if it
can be folded so that its two parts
match. The fold is called the line of
symmetry.
A pair of numbers used to locate a
point on a grid. The first number tell
you to move across the X – axis. The
second number tells you to move up
or down the Y – axis.
Y
X
3,2
Says move 3 right
Move 2 up to your point
The starting point or the ordered pair
(0
, 0)
Y
X
origin
A figure that has one or
more lines of symmetry.