1.12 Transformations
Translations
Pacing:This lesson should take one class period
Goal:The purpose of this lesson is to introduce the concept of translations (slides) in the coordinate plane.
Vocabulary!The wordisometryrefers to any type of transformation...
Did You Know?Translations are formed by a composite of reflections over parallel lines. To illustrate this in further
detail, see theReflectionslesson.
Vectors Outside the Coordinate Plane!Vectors can be used to translate an object not on a coordinate plane. A vector
in this case tells the length and direction to translate a figure. Use the diagram below.
The black ray represents the vector. Therefore, 4 ABCshould be translatedNNEthe length of the vector. The
resulting translation is pictured below.
Additional Example:
SupposeA[U+0080][U+0099]B[U+0080][U+0099]C[U+0080][U+0099]D[U+0080][U+0099]is the image ofABCD
under a translation by vectorc= (− 8 , 3 ). What are the vertices of the preimage is the image has vertices at the follow-
ing locations:A[U+0080][U+0099]= ( 0 , 0 ),B[U+0080][U+0099]= ( 1 , 5 ),C[U+0080][U+0099]= (− 4 , 4 ),D[U+0080][U+0099]=
(− 7 ,− 10 )?A=− 8 ,− 3 ),B= ( 9 , 2 ),C= ( 4 , 1 ),D= (− 1 ,− 13 )
Matrix Addition
Pacing:This lesson should take one class period
Goal:Matrices are useful in geometry, as well as algebra and business. This lesson introduces students to the basics
of matrices, namely, matrix addition.
Chapter 1. Geometry TE - Teaching Tips