1-7 transformations on the coordinate plane Chapter 1 1-7 transformations on the coordinate plane

Objectives Students will be able to: Identify reflections, rotations, and translations. Graph transformations in the coordinate plane.

What is a transformation? A transformation is a change in the position, size, or shape of a figure. The original figure is called the preimage. The resulting figure is called the image. A transformation maps the preimage to the image. Arrow notation () is used to describe a transformation, and primes (’) are used to label the image.

Types of transformations

Reflections Types of reflections: Reflection across the y-axis Reflection across the x-axis Reflection across a specific line

Example #1 Work on reflection worksheet problems 1-3

Rotation Definition of Rotation A Rotation is a transformation that turns a figure about a fixed point. More about Rotation Rotation is also called as turn. The fixed point around which a figure is rotated is called as centre of rotation.

Example#2 Lets work on problems 1-3 on rotation worksheet

Translation Every point of the shape must move: the same distance Moving a shape, without rotating or flipping it. "Sliding". The shape still looks exactly the same, just in a different place. To Translate a shape:     Every point of the shape must move: the same distance in the same direction.

Example#3 Do worksheet translation problem 1-3

Identifying transformations Identify the transformation. Then use arrow notation to describe the transformation. 90° rotation, ∆ABC  ∆A’B’C’

Example#4 Identify the transformation. Then use arrow notation to describe the transformation. reflection, DEFG  D’E’F’G’

Drawing Transformation A figure has vertices at A(1, –1), B(2, 3), and C(4, –2). After a transformation, the image of the figure has vertices at A'(– 1, –1), B'(–2, 3), and C'(–4, –2). Draw the preimage and image. Then identify the transformation. The transformation is a reflection across the y-axis because each point and its image are the same distance from the y-axis.

Example#5 A figure has vertices at E(2, 0), F(2, -1), G(5, -1), and H(5, 0). After a transformation, the image of the figure has vertices at E’(0, 2), F’(1, 2), G’(1, 5), and H’(0, 5). Draw the preimage and image. Then identify the transformation. The transformation is a 90° counterclockwise rotation.

Homework Lets work on all transformation worksheet problems 1-8

Closure Today we learn about transformations and how they work on the coordinate plane. Next class we are going to continue with chapter 2

Have a great day