Warm up Rotate P(-4, -4) 180 Rotate Q(-1, -3) 90 CCW How many lines of symmetry do the following shapes have?
Review Homework
Glide Reflections and Compositions
Compositions When two or more transformations are combined to produce a single transformation The composition of 2 (or more) isometries is an isometry.
Glide Reflections Combining a translation with a reflection If the line of reflection is parallel to the direction of translation, then it does not matter which you do first. Otherwise, order is important. In the long run, just do the first one first and the second one second.
1. Finding the Image of a Composition Perform the Glide Reflection on A(–3, 5). A’(–6, 2) A’’(2, –6)
2. Finding the Image of a Composition Perform the following composition on C(2, 0), D(3, 3) C’(2, 0), D’(3, –3) C’’(0, –2), D’’(–3, –3)
3. Finding the Image of a Glide Reflection Use the information below to sketch the image of QRS after a glide reflection. Q(2, –3), R(4, –4), and S(5, –1) Q’’(-2, 2), R’’(-4, 1), & S’’(-5, 4)
4. Describing the composition Rotation of 180° around the origin Reflection across y = 1
Rotational Symmetry of Objects What type of rotational symmetry do the figures have? You must determine the number of degrees. Spin it until it looks the same. Count how many times you can do this. Divide 360 degrees by that number.
Combinations of Transformations Practice WS Class Work Combinations of Transformations Practice WS