Unit 1:
Transformations & Symmetry
Lesson Video
Focus Standards
Learning Focus
Additional Resources
A Develop Understanding Task
Develops definitions and essential properties of rigid-motion transformations: translation, reflection and rotation.
Identify features of translations, rotations, and reflections.
What tools and strategies do I use when I translate a figure? Rotate a figure? Reflect a figure?
What do these tools and strategies reveal about the transformation?
Although each of these transformations move figures in different ways, what do they all have in common?
A Solidify Understanding Task
Determines which rigid-motion transformations will carry one image onto another congruent image, including describing a sequence of transformations precisely, by referring to the defining characteristics.
Determine the rigid transformation that carries one image onto another.
When given an image and its pre-image, what do I look for to identify a rigid transformation that has already occurred?
How do I recognize when a sequence of rigid transformations may be needed to carry one figure onto another, and how do I identify what transformations that sequence might include?
How do I justify that my proposed rigid transformation, or sequence of transformations, works?
A Practice Understanding Task
Writes and applies formal definitions of the rigid-motion transformations. Notices that two reflections over non-parallel lines is the same as a rotation.
Write precise definitions of the rigid transformations.
How do I use my intuition, and the insights gained during the past few tasks, to identify or produce a rigid transformation?
How can I make my intuitive and insightful thinking explicit in words and diagrams?
What can I add to the words slide, flip, and turn to more precisely define the rigid transformations—translation, reflection, and rotation?
A Develop Understanding Task
Finds rotational symmetry and lines of symmetry in special types of quadrilaterals.
Identify transformations that carry an image onto itself.
What does it mean to say that a figure is symmetrical?
How is symmetry related to rigid transformations?
A Solidify Understanding Task
Examines properties about regular polygons based on their rotational symmetry and lines of symmetry.
Find patterns of line and rotational symmetry in regular polygons.
What makes a polygon regular or symmetric?
How does the symmetry of regular polygons differ depending on the number of sides?
What patterns can I find in the number and characteristics of the lines of symmetry in a regular n-gon (a polygon with n sides)?
What patterns can I find that describe the nature of the rotational symmetry in a regular n-gon?
Lesson 6: Quadrilaterals: Beyond Definition
A Practice Understanding Task
Makes and justifies conjectures about properties of quadrilaterals using transformations.
Relate attributes of special quadrilaterals to symmetry.
What else might be true about parallelograms, rectangles, squares, or rhombuses other than the characteristics given about them in their definitions?
How might I be convinced that certain characteristics must occur in every member of a special class of quadrilaterals?