Warm up was an angle chase involving parallel lines and triangles. Launched transformations unit with a video showing a marching band performing an elaborate routine (video here). Then looked at reflectional and rotational symmetry through nature and art, including flowers and viruses. Defined congruence by looking at a "spot the differences" picture and noting that the way to find ~all~ differences at once is to overlay one image on the other. This leads to the definition of congruence in terms of rigid motions, which we used to describe how a hexagon might lay atop another. Then performed a transformation on the coordinate plane (a translation) which introduced arrow notation and the notion of pre-image and image. Finally, we used our vocabulary on transformations to describe the movement of Ms Pacman who moves in a combination of translations, rotations, and reflections to move in the video game.
Notes from the board
Homework
p. 106-107 #8-11
Resources
translating a figure on the coordinate plane: link
write a rule for a translation: link
Warm up was to finish the Pacman task from last class. Went over homework, then did a test prep question related to combining rotations and reflections. Learned about vectors and how they can be used to describe translations. Performed a translation and also described a translation using vectors. Then moved into reflections, where we defined the operation, then reflected across the two axes, and across y=x and y=-x, each of which had particular, ordered rules for how the coordinates transform under reflection.
Notes from board
Homework
this handout (skip #1, 6, 10, 11)
Resources
performing a reflection across non-axis lines (made by me!) link
identifying the line of reflection (made by me!) link
translating a figure on the coordinate plane: link
reflecting a figure across x or y axis: link
reflecting across various lines: link
basics of translation link
write a rule for a translation: link