Common Core Math - Grade 8

Lesson Plan

Describe the effect of dilations, translations, rotations, and reflections on two-dimensional figures using coordinates

Goals / Objectives

Apply the coordinate rules for translations, reflections (across the x-axis and y-axis), rotations (90 degrees, 180 degrees, 270 degrees about the origin), and dilations (centered at the origin) to compute the image of a given point or set of vertices

Describe the effect of each transformation on the coordinates of a figure using precise coordinate notation -- for example, "a reflection across the y-axis maps (x, y) to (-x, y)"

Classify a transformation as rigid (translation, reflection, rotation) or non-rigid (dilation) and explain how the coordinate rules reveal whether side lengths are preserved or changed

Determine the image of a two-dimensional figure (triangle, rectangle, or other polygon) under a single transformation by applying the coordinate rule to every vertex, then plotting the image on the coordinate plane

Compare the pre-image and image of a figure under dilation with the pre-image and image under a rigid motion, articulating that dilation changes the size but preserves the shape, while rigid motions preserve both

Standards

8.G.A.3

8.G.A.3: Describe the effect of dilations, translations, rotations, and reflections on two-dimensional figures using coordinates.

Academic Vocabulary

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Accommodations

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Anticipatory Set / Bell Work

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Check for Understanding

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Guided Practice

Independent Practice