Symmetry

1. 9.6 Symmetry
February 19, 2014
Bellwork
In exercises 2 and 3, use the quadrilateral HIJK with
vertices H(3, 0), I( 1,–4), J(0, –4), K(–1, –3).
2. Use the coordinate rules to name the vertices of
the image of HIJK for a rotation of 180° about the
origin.
H′ (­3, 0), I′(­1, 4), J′(0, 4), K′(1, 3)
3. Use matrix multiplication to find the image
matrix that represents a 270° rotation of HIJK about
the origin.
H′ I′ J′ K′
[
0 –4 –4 –3
–3 –1 0 1
]
Feb 7­7:20 AM
HW pg. 621 #3­14, 17­20
1

2. 9.6 Symmetry
February 19, 2014
9.6 Identify Symmetry
line of symmetry: line where figure can be mapped onto itself by a
reflection.
Feb 7­7:57 AM
HW pg. 621 #3­14, 17­20
2

3. 9.6 Symmetry
February 19, 2014
Rotational Symmetry: if figure can be mapped onto itself by a
rotation of 180 or less
Center of Symmetry: center of figure
Feb 7­8:00 AM
HW pg. 621 #3­14, 17­20
3

4. 9.6 Symmetry
February 19, 2014
Point Symmetry: when every part has a matching part.
Feb 7­8:18 AM
HW pg. 621 #3­14, 17­20
4

5. 9.6 Symmetry
February 19, 2014
HW
pg. 621
#3-14,
17-20 all
Feb 7­8:21 AM
HW pg. 621 #3­14, 17­20
5