Sewanhaka High School
Math 8
Class:________________
Name:________________________________
Mrs. Lidowsky, Principal
Mr. Long, Teacher
Date:_____________________
H.W. #48: Ditto
DO-NOW #48:
1) Locate quadrilateral ABCD by plotting and connecting the
following points: A(1, 1) B(1, 4) C(5, 4) D(5, 1)
a) Find the area of the figure
b) Find the image of ABCD under rx-axis. Label it A’B’C’D’.
c) Find the image of ABCD under ry-axis. Label it A’’B’’C’’D’’.
d) Find the image of ABCD under ry=x. Label it A’’’B’’’C’’’D’’’
e) Give the coordinates for each figure in parts b, c, and d
2) Add:
2 5
+ =
3 9
Topic: Transformations
Main Idea: Point Reflections
Aim:
RECALL
NOTES
Locate ΔABC by plotting and connecting the following points: A(1, 1) B(1, 4) C(4, 1)
Using a ruler, draw a line from point A to the origin. Don’t pick up your ruler. Extend the segment the same
distance on the other side. Label the endpoint A’. Do the same for points B and C. Do the same for B and C.
Look at the coordinates of the
images, how can you find the
image of a point under a
reflection in the origin without
graphing?
Find the area of both figures
Locate ABCD by plotting and connecting the
following points: A(-1, 2) B(-2, 0) C(-5, 0)
D(-4, 2)
Find the image of ABCD under a reflection in the
origin. Give the coordinates of A’, B’, C’, and D’.
Answer:
A(-1, 2) →
Find the area of each
B(-2, 0) →
figure.
C(-5, 0) →
D(-4, 2) →
Locate point A and point B by plotting the
following points: A(-1, 2) B(2, 0)
Find the image of A under a reflection in point B.
Give the coordinates of A’.
(To do this, plot A and B. Show the slope from point A to point B
and then use the same slope to go from point B to point A’. It can
also be done with a ruler.)
Answer:
A(-1, 2) →
Locate point C and point D plotting the following
points:
C(2, 4) D(3, 6)
Find the image of C under a reflection in point D.
Label it C’. Give the coordinates of C’.
Answer:
C(2, 4) →
Pg. 3
DRILL:
D’( ,
E’( ,
F’( ,
)
)
)
Find the area of each triangle.
How does the size and shape of
∆DEF compare with that of ∆D’E’F’?
Locate point E and point F by
plotting the following points: E(2, 6)
F(-3, 4)
Find the image of E under a reflection
in point F. Give the coordinates of
E’.
Answer:
E(2, 6) →
Locate point C and point D plotting
the following points:
C(-4, -4) D(1, -7)
Find the image of C under a
reflection in point D. Label the
image C’.
Give the coordinates of C’.
Answer:
C(-4, -4) →
Summary: