Back to Understand that a two-dimensional figure is congruent to another if the second can be obtained from the first by a sequence of rotations, reflections, and translations — Problem 2 · Task Set 22

Exercises: Congruence Through Sequences of Rigid Motions

Work through each section in order. When you describe a sequence of rigid motions, name each transformation in order and give its parameters: direction and distance for a translation, the line of reflection for a reflection, and the center and angle (with direction) for a rotation. Two figures are congruent only when a sequence of rigid motions maps one exactly onto the other.

Grade 8·21 problems·~35 min·Common Core Math - Grade 8·container·8-g-a-2
Work through problems with immediate feedback
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Fluency Practice

For each pair of congruent figures, describe a sequence of rigid motions that maps the first onto the second. Name each transformation in order, with its parameters.

A coordinate grid showing solid triangle ABC in the first quadrant and a congruent dashed triangle DEF turned around in the third quadrant.
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Triangle ABCABC has vertices A(1,1)A(1, 1), B(4,1)B(4, 1), C(1,3)C(1, 3). Triangle DEFDEF has vertices D(1,1)D(-1, -1), E(4,1)E(-4, -1), F(1,3)F(-1, -3). A single motion is not enough. Describe a sequence of two rigid motions that maps ABCABC onto DEFDEF, naming each step in order.