Curriculum / Math / 8th Grade / Unit 3: Transformations and Angle Relationships / Lesson 9
Math
Unit 3
8th Grade
Lesson 9 of 22
Jump To
Lesson Notes
There was an error generating your document. Please refresh the page and try again.
Generating your document. This may take a few seconds.
Are you sure you want to delete this note? This action cannot be undone.
Describe multiple rigid transformations using coordinate points.
The core standards covered in this lesson
8.G.A.2 — 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; given two congruent figures, describe a sequence that exhibits the congruence between them.
8.G.A.3 — Describe the effect of dilations, translations, rotations, and reflections on two-dimensional figures using coordinates.
The essential concepts students need to demonstrate or understand to achieve the lesson objective
Suggestions for teachers to help them teach this lesson
Unlock features to optimize your prep time, plan engaging lessons, and monitor student progress.
Problems designed to teach key points of the lesson and guiding questions to help draw out student understanding
25-30 minutes
Point $$A$$ is located at $${ (2, 4)}$$. Perform the following transformations on point $$A$$, and label each new point with its letter and coordinates. What impact does each transformation have on the coordinates of point $$A$$?
a. Translate point $$A$$ 2 units to the right and 4 units down. Label it point $$W$$.
b. Rotate point $$A$$ $${90^{\circ}}$$ counter-clockwise about the origin. Label it point $$X$$.
c. Reflect point $$A$$ over the $$x$$-axis. Label it point $$Y$$.
d. Reflect point $$A$$ over the $$y$$-axis. Label it point $$Z$$.
Upgrade to Fishtank Plus to view Sample Response.
Figure $${{DEF}}$$ underwent two translations, and the coordinate points after each translation are shown below.
a. Describe the translation from $${{DEF}}$$ to $${D'E'F'}$$.
b. What is the coordinate point for point $${F''?}$$
An isosceles trapezoid has coordinate points $${A(-1,2)}$$, $${B(3,2)}$$, $${C(4,-1)}$$, $${D(-2,-1)}$$.
If the trapezoid is reflected over the $$y$$-axis, what will be the coordinates of point $${B'}$$? Of point $${D'}$$?
A set of suggested resources or problem types that teachers can turn into a problem set
15-20 minutes
Give your students more opportunities to practice the skills in this lesson with a downloadable problem set aligned to the daily objective.
A task that represents the peak thinking of the lesson - mastery will indicate whether or not objective was achieved
5-10 minutes
The figure shown below undergoes two transformations. First, it is reflected across the $$x$$-axis. Then the reflected image is translated $$3$$ units to the left and $$4$$ units up.
a. Explain how you can determine the coordinates for point $${E'}$$ after the two transformations.
b. Victoria determines that the new coordinates for point $$D$$ after the two transformations will be $${{(-5,5)}}$$. She says that after the reflection, point $$D'$$ is located at $${(-2,1)}$$, and then the translation maps it to $${{(-5,5)}}$$. Is Victoria correct? Explain why or why not.
The following resources include problems and activities aligned to the objective of the lesson that can be used for additional practice or to create your own problem set.
Next
Review rigid transformations and congruence between two figures.
Topic A: Congruence and Rigid Transformations
Understand the rigid transformations that move figures in the plane (translation, reflection, rotation).
Standards
8.G.A.1.A8.G.A.1.B8.G.A.1.C8.G.A.2
Describe and perform translations between congruent figures. Use translations to determine if figures are congruent.
Describe and apply properties of translations. Use coordinate points to represent relationships between translated figures.
8.G.A.1.A8.G.A.1.B8.G.A.1.C8.G.A.28.G.A.3
Describe and perform reflections between congruent figures. Use reflections to determine if figures are congruent.
Describe sequences of transformations between figures using reflections and translations. Use coordinate points to represent relationships between reflected figures.
Describe and perform rotations between congruent figures.
Describe sequences of transformations between figures using rotations and other transformations.
Describe a sequence of rigid transformations that will map one figure onto another.
8.G.A.28.G.A.3
Create a free account to access thousands of lesson plans.
Already have an account? Sign In
Topic B: Similarity and Dilations
Define a dilation as a non-rigid transformation, and understand the impact of scale factor.
8.G.A.4
Describe and perform dilations.
Describe a sequence of dilations and rigid motions between two figures. Use coordinate points to represent relationships between similar figures.
8.G.A.38.G.A.4
Determine and informally prove or disprove if two figures are similar or congruent using transformations.
8.G.A.28.G.A.4
Find missing side lengths in similar figures. Find scale factor between similar figures.
Use properties of similar triangles to model and solve real-world problems.
Topic C: Angle Relationships
Define and identify corresponding angles in parallel line diagrams. Review vertical, supplementary, and complementary angle relationships.
8.G.A.28.G.A.5
Define and identify alternate interior and alternate exterior angles in parallel line diagrams. Find missing angles in parallel line diagrams.
Solve for missing angle measures in parallel line diagrams using equations.
8.G.A.5
Define and use the interior angle sum theorem for triangles.
Define and use the exterior angle theorem for triangles.
Define and use the angle-angle criterion for similar triangles.
See all of the features of Fishtank in action and begin the conversation about adoption.
Learn more about Fishtank Learning School Adoption.
Yes
No
We've got you covered with rigorous, relevant, and adaptable math lesson plans for free