options: Use geometric descriptions of rigid motions to transform figures and to predict the effect of a given rigid motion on a given figure; given two figures, use the definition of congruence in terms of rigid motions to decide if they are congruent.

Explain how the criteria for triangle congruence (ASA, SAS, and SSS) follow from the definition of congruence in terms of rigid motions.

Use the definition of congruence in terms of rigid motions to show that two triangles are congruent if and only if corresponding pairs of sides and corresponding pairs of angles are congruent.
problem_activity: Problem 1
Describe whether the following statement is always, sometimes, or never true:
“If you reflect a figure across two parallel lines, the result can be described with a single translation rule.”
Problem 2
Describe whether the following statement is always, sometimes, or never true:
“The reflection of a figure over two unique lines of reflection can be described by a rotation.”
Problem 3
Johnny says three rotations of
$${90^{\circ}}$$
about the center of the figure is the same as three reflections with lines that pass through the center, so a figure with order 4 rotational symmetry results in a figure that also has reflectional symmetry.
Describe, using evidence from the two drawings below, to support or refute Johnny’s statement.
[IMG]


correct_option_index: 0