Mathematics (2019) Grade(s): 7 - Grade 7 Accelerated

MA19.7A.42

Verify experimentally the properties of rigid motions (rotations, reflections, and translations): lines are taken to lines, and line segments are taken to line segments of the same length; angles are taken to angles of the same measure; and parallel lines are taken to parallel lines.

Unpacked Content

Knowledge

Students know:
  • how to measure line segments and angles
  • That similar figures have congruent angles.
  • The definition/concept of what a figure does when it undergoes a rotation, reflection, and translation.
  • how to perform a translation, reflection, and rotation.

Skills

Students are able to:
  • verify by measuring and comparing lengths of a figure and its image that after a figure has been translated, reflected, or rotated its corresponding lines and line segments remain the same length.

Understanding

Students understand that:
  • congruent figures have the same shape and size.
  • Two figures in the plane are said to be congruent if there is a sequence of rigid motions that takes one figure onto the other.

Vocabulary

  • Congruent
  • Rotation
  • Reflection
  • Translation
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