Mathematics (2019) Grade(s): 09-12 - Geometry with Data Analysis

MA19.GDA.27

Given two figures, determine whether they are similar by identifying a similarity transformation (sequence of rigid motions and dilations) that maps one figure to the other.

Unpacked Content

Knowledge

Students know:
  • Properties of rigid motions and dilations.
  • Definition of similarity in terms of similarity transformations.
  • Techniques for producing images under a dilation and rigid motions.

Skills

Students are able to:
  • Apply rigid motion and dilation to a figure.
  • Explain and justify whether or not one figure can be obtained from another through a combination of rigid motion and dilation.

Understanding

Students understand that:
  • A figure that may be obtained from another through a dilation and a combination of translations, reflections, and rotations is similar to the original.
  • When a figure is similar to another the measures of all corresponding angles are equal, and all of the corresponding sides are in the same proportion.

Vocabulary

  • Similarity transformation
  • Similarity
  • Proportionality
  • Corresponding pairs of angles
  • Corresponding pairs of sides
  • Rigid Motion
ALSDE LOGO