ASSUMPTIONS: It is assumed that the students are very proficient in their use of a computer and well acquainted with the GSP program.
OBJECTIVES:
(1) The students will know the meaning of transformations and the four types, concentrating on TRANSLATION for today's lesson.
(2) The students will know the properties of translation.
(3) The students will be able to use GSP to transform an object by translation.
PROCEDURES: (1) Lecture on subject and related use of the GSP program.
(2) Discussion, answering students questions.
(3) Individual work on computers.
LECTURE/ CLASSWORK:
I. WHAT IS A TRANSFORMATION?
A. The movement of a sketched object from its original position to another position.
B. Types:
1) TRANSLATION (sliding)
2) ROTATION (turning)
3) DILATION (shrinking/enlarging)
4) REFLECTION (flipping over)
C. Objects of transformation:
1) the original sketched object
2) the "moved" object (the "image" of the original one).
II. TRANSLATION
A. Sliding
(1) Think of the object sliding on the screen from the original point X to the new location at point X'.
(2) Think of movement along x-axis and y-axis (use a computer-linked overhead to illustrate movement on a graph grid)
(3) Whole object is moved-not just part.
(4) Every point of object is equidistant to its prime:
B. Shape
(1) Translation does not change size, shape, or orientation of object.
(2) Change only in object's location
III. COMPUTER WORK
A. Maximum of two persons per computer
B. Use GSP's coordinate-grid
C. How to find new coordinates?
(1) You are given a point X and the translating coordinate.
(2) How to find X'?
(a) Add the "x" coordinates of both the X point and the translating coordinate to derive the new "x" coordinate for X'.
(b) Add "y" coordinates of both the X and the translating coordinate to derive the new "y" coordinate for X'= (x', y').
D. Give a point for students to translate
(1) Point (2,3) translated by (3,1)- resulting coordinates?
(2) Point (2,3) translated by (-3, -1)- resulting coordinates?
E. Give triangle's vertices coordinates to be translated
(1) (1,2), (3,3), and (5,1)---[put on board]
(2) Translate by (3, 2)
F. Measure distance from each X point to its corresponding X' point.
(1) Mark point A and A'- click "measurement" to find its length.
(2) Do same for B and B'.
(3) Do same for C and C'.
(4) Are all the measurements the same? They should be!
G. Have list of coordinates already on board for students to work with (or supply handout with the info).
(1) Students work by self (or by twos).
(2) I will walk around and observe.
(3) I will be available to help students and to answer questions.
IV. REGROUP
A. Students back at desks.
B. Retiterate what happened in class today.
V. DISMISS