Description
please wright clear and neat thank you.
Unformatted Attachment Preview
Geometry
Period____
Name____________________
Date_____________________
Symmetry
Essential Question: What is the relationship between rigid motions and congruence?
DO NOW :
Guided Practice:
Example # 1: Identify Transformations for Symmetry
You Try!
Example #2: Identify Lines of Symmetry
You Try !
Example #3: Identify Rotational Symmetry
You Try!
Exit Ticket:
a- How many lines of symmetry does a regular five-pointed star have?
b- Find all transformations that can be used to map each figure onto itself.
Name
LESSON
Reteach
Date
Class
12-5 Symmetry
A figure has symmetry if there is a transformation of the figure such that the image and
preimage are identical. There are two kinds of symmetry.
The figure has a line of symmetry that divides the figure into
two congruent halves.
Line Symmetry
Rotatio
nal
Symmetry
one line of
symmetry
two lines of
symmetry
no line
symmetry
When a figure is rotated between 0° and 360°, the resulting
figure coincides with the original.
• The smallest angle through which the figure is rotated to coincide with
itself is called the angle of rotational symmetry.
• The number of times that you can get an identical figure when repeating
the degree of rotation is called the order of the rotational symmetry.
angle:
order:
180°
2
120°
3
no rotational
symmetry
Tell whether each figure has line symmetry. If so, draw all lines
of symmetry.
1.
2.
Tell whether each figure has rotational symmetry. If so, give the angle
of rotational symmetry and the order of the symmetry.
3.
4.
X
Copyright © by Holt,
Rinehart and Winston. All rights
reserved.
38
Holt
Geometry
Name
LESSO
N
Reteach
12-5 Symmetry
continued
Three-dimensional figures can also have
symmetry.
Date
Class
Symmetry in
Three
Descriptio
n
Example
Dimensions
Plane Symmetry
A plane can divide a figure into two
congruent halves.
Symmetry
About an Axis
There is a line about which a figure
can be rotated so that the image and
preimage are identical.
A cone has both plane symmetry and symmetry
about an axis.
Tell whether each figure has plane symmetry, symmetry about an
axis, both, or neither.
5. square pyramid
6. prism
7. triangular
pyramid
Copyright © by Holt, Rinehart and
Winston.
All rights
reserved.
8.
cylinder
0
0
39
Holt
Geometry
Geometry
Period____
Name____________________
Date_____________________
Quiz # 5
The vertices of a figure are given. Rotate the figure as described. Find the coordinates of
the image.
1-
2-
3-
4-
Geometry
___________________
Period__2__
2024__________________
Name_Katrina Lee
Date___1-8-
Geometry Final Exam Review
1- B, D.
2- Points A, B, and C are collinear and B lies between A and C. If AC = 48, AB = 2x + 2, and
BC = 3x + 6, what is BC?
3-
4- What is an expression for the distance between the origin and a point P(x, y)?
5-
6-
7- In the figure shown, t II x and k II w
the other angles that measure 20°.
8-
and . Choose the list which includes all of
9-
10-
11-
12-
13-
14-
15-
16-
Purchase answer to see full
attachment
