Page 885 - Algebra 1

Transformations in the Coordinate Plane
Skills Bank Lesson 24
A transformation is a change in the size or position of a figure. If you transform the preimage, or original figure ABC, then the transformed figure, or image, is named A′B′C′. Transformations include translations or slides, reflections or flips, and rotations or turns. Preimages and images are congruent for all transformations.
Example
1
Finding Transformations
a. Reflect △ABC across the y-axis.
b. Translate △ABC 3 units left and 4 units down.
O
O
-4
-2
-2
y
A
2
O
y
4
A
B
2
C
x
B
-4
-2
-4
C
-2
2
4
SOLUTION
The y-axis is a line of symmetry.
SOLUTION
Move each vertex 3 units left and 4 units down.
-4
y
4
4
A
B
2
2
x
O
C
x
-2
A´
A
2
-4 A´
B´
B
C´
C
-4
-4
B´
4
C´
Skills Bank Practice
a. Reflect △ABC across the y-axis.
b. Give the coordinates for the points that describe the translation 5 units left.
y
4
B
4
y
2
O
x
2
A
-4
-2
-2
A
2
4
-4
-2
O
x
C
-2
-4
B
2
D
-4
870 Saxon Algebra 1
4
2
y
x
C