Transformations unit
Understand congruence and similarity using physical models, transparencies, or geometry
software.
8.G.A.1.A.B.C.
Verify experimentally the properties of rotations, reflections, and translations:
Lines are taken to lines, and line segments to line segments of the same length.
Angles are taken to angles of the same measure.
Parallel lines are taken to parallel lines.
_____1. I can define transformations including rotations, reflections and translations.
_____2. I can identify transformations including rotations, reflections and translations.
_____3. I can identify the center of movement as my origin or another point or line.
_____4. I can identify corresponding sides and angles
_____5. I can identify the line of reflection.
_____6. I can identify and use symbols for pre and post images using coordinates for
rotations, reflections and translations.
_____7. I can determine the measure of rotation as 45, 90, 180, 270 or 360 degrees
around the point of origin
_____8. I can determine the changes in the ordered pairs after the translation has taken
place.
_____9. I can determine the changes in the ordered pairs after a reflection has taken
place.
_____10. I can rotate figures by 45, 90, 180, 270 or 360 degrees around the point of
origin and determine the changes in the ordered pairs after the rotation has taken place.
_____11. I can demonstrate properties of rotations, reflections, and translations by
graphing and identifying lines to lines, segments to segments, angles to angles and
parallel lines to parallel lines.
8.G.A.2
Understand that a two-dimensional figure is congruent to another if the second can be
obtained from the first by a sequence of rotations, reflections, and translations; given two
congruent figures, describe a sequence that exhibits the congruence between them.
_____a. Given two congruent figures, I can describe the sequence of events in the
transformation from pre image to post image. This description can be in words, symbols
and notations.
_____b. I can explain why two figures are congruent after performing a transformation.
_____c. I can apply the concept of congruency to write congruent statements.
_____d. I can reason that a 2d figure is congruent to another if the second can be
obtained by a sequence of rotations, reflections and translations.
8.G.A.3
Describe the effect of dilations, translations, rotations, and reflections on twodimensional figures using coordinates.
_____a. I can identify scale factors of the dilation.
_____b. I can describe the effect of transformations- rotations, reflections, translations,
dilations using coordinates or ordered pairs of 2d figures.
_____c. I can describe the effect transformations have on the ordered pairs of the figure.
8.G.A.4
Understand that a two-dimensional figure is similar to another if the second can be
obtained from the first by a sequence of rotations, reflections, translations, and dilations;
given two similar two-dimensional figures, describe a sequence that exhibits the
similarity between them.
_____a. Given two similar figures, I can describe the sequence of events in the
transformation from pre to post image.
_____b. I can define similar figures as corresponding angles that are congruent and
corresponding sides are proportional.
_____c. I can recognize the symbol for similar.
_____d. I can draw a parallel line inside a triangle and use it to prove the two are similar
based on ratios.
_____e. I can apply the concepts of similarity to write similarity statements.
_____f. I can reason that a 2d figure is similar to another and the 2nd can be obtained by
a sequence of rotation, reflection, translation and dilation.
Vocabulary: transformations, translation, dilation, reflection, rotation, point of
origin, similar, congruent