Warm up
What type of transformation is shown? Write the algebraic representation.
Write the coordinates of the original triangle after reflection over
X- axis:
Y-axis:
Rotations
A turn around a center.
The distance from the center to any
point on the shape stays the same.
Rotational Symmetry
Any figure that can be
turned or rotated less
than 360° about a fixed
point so that the figure
looks exactly as it does
in its original position.
Rotate 90 Clockwise
about the Origin
(Same as 270 Counterclockwise)
 x,y    y,  x 
Change the sign of x and switch the order
Rotate 90° clockwise
about the origin
A(7, 3) 
 A'(
B(1, 4) 
 B'(
C(3, 1) 
 C'(
,
,
)
)
,
)
Rotate 90° clockwise
about the origin
A(7, 3)  A'  3,7 
B(1, 4)  B'  4, 1
C(3, 1)  C' 1, 3 
Rotate 180 clockwise about
the origin
 x,y     x,  y 
ONLY Change the signs
Rotate 180° clockwise about the
origin
Q(8,  2) 
 Q'(
,
)
R(8,  9) 
 R'(
,
)
S(2,  2) 
 S'(
,
)
T(2,  9) 
 T '(
,
)
Rotate 180° about the origin
Q(8,  2)  Q'  8,2 
R(8,  9)  R'  8,9 
S(2,  2)  S'  2,2 
T(2,  9)  T '  2,9 
Rotate 270 clockwise about
the Origin
 x,y     y, x 
Change the sign of y and switch the order
Rotate 270° clockwise
about the origin
E(3,  2) 
(
,
)
F(6, 5) 
(
,
)
G(0, 2) 
(
,
)
Rotate 270° clockwise
about the origin
E(3,  2)  E'  2, 3 
F(6, 5)  F'  5, 6 
G(0, 2)  G'  2,0 
Rotation 180 degrees about the origin
Rotation 270 degrees about the origin
Or 90 degree counter clockwise about the origin
Rotation 90 degrees about the origin
Write down the coordinates of the image after
each transformation.
Write a rule to describe each transformation
90 degree rotation
180 degree rotation
Homework
Rotations HW
Worksheet