Transformations and Symmetry Objective: Students will be able to perform and identify types of transformations.

Rigid Transformation – when you transform the figure and get a congruent image, same rule to all points Non-Rigid Transformation – you transform the figure and get a similar or non congruent figure, when you enlarge or shrink a figure, different rule to all points

Translation To move a figure along the x-axis, the y-axis or both Moving a figure along the x-axis all the x coordinates are changed the same (same rule), all subtracted 4 Moving a figure along the y-axis all the y coordinates are changed the same, all added 3 Moving a figure on both the x and y, all points on x moved the same, all points on y moved the same

Rotational Transformation Rotate the figure around a fixed point a fixed amount of degrees Can rotate clockwise or counter clockwise We will only discuss 90, 180 and 270 degrees

Rotated Shape counterclockwise around the origin

Reflection Transformation Reflect figure over a fixed line to get a mirror image of the figure The line the figure is reflected over is the perpendicular bisector of the segment connecting the figure and the image Mirror the distance on each side and flip the figure

Reflected on the y-axis, notice the y-axis is the line of symmetry, each point is the same distance away just on the opposite side

Reflection Conjecture The line of reflection is the perpendicular bisector of every segment joining a point in the original figure with its image.

Transformations We will discuss both doing the transformation stated and stating what the transformation is given the original and new picture

Homework Worksheets on Transformations Practice one side do the other

Multi Step Transformations Some multi step transformations result in the same single transformation Do two translations could be rewritten as a single translation A reflection over x then y axis could be a rotation of 180 Combination of 2 different transformations

Reflection Symmetry If the figure can be reflected over a line in such a way that the resulting image, coincides with the original, can you fold the figure over this line to get it to lie on top of itself Place a mirror on the line to complete the figure

How many lines of symmetry does this figure have, lines of symmetry can be diagonal 1. Can you think of a letter in the alphabet that has a vertical line of symmetry? Horizontal line? Diagonal? More than one? A Word? This isosceles triangle has one line of symmetry, down the middle, splits it in half

Rotational Symmetry If a figure can be rotated about a point in such a way that its rotated image coincides with the original figure before turning 360 degree N-fold rotation, n is how many times you can rotate the figure, need to rotate at least twice Turn a square around 4 times and they all look the same Turn a rectangle around 2 times, 2-fold rotation

This figure has no rotational symmetry, I can not turn it and get the exact same shape as my original

How many times can you rotate this figure and get the same shape, do not count the original, but count it when you return to the original position Can you think of a letter, figure or word that has rotational symmetry?

Objective: Students will be able to perform and identify types of transformations. On a scale of 1 to 4 Do you feel we meet the objective for the day. If we did not meet the objective, what did we miss and how could I improve.

Homework Symmetry Worksheet