Common Core State Standards Grades 9 - 12 Mathematics Training
Work Session 4: Unpacking Worksheet for CCSS Grades 9 - 12
Sample for CCSS G-SRT. 2
Directions: For the standard listed below, identify the prerequisite skills, key terms and
verbs, and corresponding definitions. Create a series of “I Can” statements and Essential
Questions.
G-SRT.2: Given two figures, use the definition of similarity in terms of similarity transformations to
decide if they are similar; explain using similarity transformations the meaning of similarity for triangles
as the equality of all corresponding pairs of angles and the proportionality of all corresponding pairs of
sides.
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This standard will be assessed in: ________Algebra I
___ Algebra II
Geometry
Course Emphases: ___Major Content
Supporting Content
_______ Additional Content
Connections to CCSS: _____________________________________________________________
Prerequisite Skills
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Rigid motion: reflection, translation, rotation. Rigid motions move a figure while preserving its size and shape.
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Dilation: a transformation that moves each point along the ray through the point emanating from a fixed center,
and multiplies the distances from the center by a common scale factor. It is a rescaling along radial lines centered
at a point. The scale factor is the ratio of the any length to its dilated image.
Key Terms (vocabulary)
Definition
Student-friendly language
 Similarity
 When one figure is the image of the
other under a transformation from
the plane into itself that multiplies all
distances by the same positive scale
factor, k.
 Same shape, different size
 Similarity transformation
 ___________________________
 A slide, flip or turn followed by a rescaling
 Corresponding
 Relative position of two parts is the
same
 Matching
 Proportionality
 A ratio of two quantities that is
constant
Key Verbs (skills)
Definition
Student-friendly language
 Use
 To put into service or apply
 Apply
 Explain
 To make plain or clear
 Give details
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“I Can” statements in student-friendly language
I can move figures through sliding, flipping or turning it.
I can then change its size by enlarging or shrinking it.
I can change the position and size of an object but maintain its shape.
Essential Questions
Can a figure be mapped onto itself by a sequence of rigid motions and dilations? What is the
relationship between this mapping and the corresponding parts of the figure?
Are the corresponding parts congruent? Are they similar?