EngageNY
Characterize Points on a Perpendicular Bisector
Learn transformations through constructions! Pupils use perpendicular bisectors to understand the movement of a reflection and rotation. They discover that the perpendicular bisector(s) determine the line of reflection and the center of...
EngageNY
Definition of Translation and Three Basic Properties
Uncover the properties of translations through this exploratory lesson. Learners apply vectors to describe and verify transformations in the second installment of a series of 18. It provides multiple opportunities to practice this...
Illustrative Mathematics
Congruent Triangles
Geometers prove that triangle PQR is congruent to triangle ABC by describing any combination of rotations, reflections, and translations that would prove it so. There is only this single task on the handout, but a detailed explanation of...
Curated OER
Why Does ASA Work?
Your geometry learners explore Angle-Side-Angle congruence in this collaborative task. The sum of the interior angles of all triangles being one hundred eighty degrees, is the key learners will discover as they explain their reasoning...
Curated OER
Who Said Math Can't Be Fun?
With these innovative ideas, demonstrate to your class that math doesn't always have to be hard work.
Shodor Education Foundation
An Introduction To Quadrilaterals
Young geometers investigate and apply properties of quadrilaterals. After a review and discussion of key terms, students use a computer applet to explore four-sided figures and classify them according to their attributes. The...
Curated OER
Is This a Rectangle?
How do you show that something is a rectangle? This activity starts with four coordinate points and asks young geometers to explain whether they create a rectangle. Knowledge from both geometry and algebra come into play here, as well...
Curated OER
Point Reflection
Use this task as an exit ticket for your eight graders during the geometry unit. All they need to do is identify the coordinates of a point reflected over y=2000.
Curated OER
Reflected Triangles
Your learners find and construct the line of reflection between a triangle's pre-image and its reflection image in this short activity.
Mathematics Vision Project
Circles: A Geometric Perspective
Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...
EngageNY
Reflections
Facilitate creativity in your math class as individuals learn the definition of a geometric reflection and correctly construct a model, as well as its reflected image. They use a perpendicular bisector and circles to elaborate on...
EngageNY
Transformations—The Next Level
Transform your geometry instruction by incorporating role play into math class. Pupils begin by completing an assessment to locate unknown angles, and then performing a simulation activity to better understand rotations, reflections, and...
EngageNY
Are All Parabolas Congruent?
Augment a unit on parabolas with an instructive math activity. Pupils graph parabolas by examining the relationship between the focus and directrix.
EngageNY
Base Angles of Isosceles Triangles
Build confidence in proofs by proving a known property. Pupils explore two approaches to proving base angles of isosceles triangles are congruent: transformations and SAS. They then apply their understanding of the proof to more complex...
EngageNY
What Lies Behind “Same Shape”?
Develop a more precise definition of similar. The lesson begins with an informal definition of similar figures and develops the need to be more precise. The class learns about dilations and uses that knowledge to arrive at a mathematical...
EngageNY
Rotations of 180 Degrees
What happens when rotating an image 180 degrees? The sixth activity in the series of 18 takes a look at this question. Learners discover the pattern associated with 180-degree rotations. They then use transparency paper to perform the...
EngageNY
Sequencing Rotations
Discover the result of a sequence of rotations about different centers. Pupils perform rotations to examine the patterns. They also describe the sequence of rotations that performed to reach a desired result in the ninth installment in a...
EngageNY
More on the Angles of a Triangle
Angles and triangles: they're all connected. Uncover the connections between angles in triangles. Scholars learn how to find both exterior and interior angle measures in triangles. The lesson emphasizes the vocabulary related to these...
EngageNY
End-of-Module Assessment Task - Grade 8 Mathematics (Module 2)
Can your classes apply the knowledge they have learned? Use this performance task to find out! Individuals use transformations to explain congruence and angle relationships within parallel lines to find missing values. They show what...
EngageNY
Converse of the Pythagorean Theorem
Discover a new application of the Pythagorean Theorem. Learners prove and apply the converse of the Pythagorean Theorem in the 17th lesson in a 25-part series. The examples ask learners to verify right triangles using the converse of the...
Curated OER
Geometry Practice Exam
In this reflections and rotations activity, students reflect and rotate lines in graphs and draw lines of symmetry through patterns. Students complete 24 problems.
Curated OER
Geometry Exam
In this reflections and symmetry activity, students draw lines of symmetry in shapes and patterns and reflect letters over lines in graphs. Students complete 20 problems.
Curated OER
Translations, Reflections and Rotations
Fifth graders use the Internet to learn about translations, reflections and rotations. Students access the Transmographer program on the Internet, where they practice what they have learned. Students also complete a worksheet.
Curated OER
An Introduction to Quadrilaterals
Students explore the concept of quadrilaterals. For this quadrilateral lesson, students play with a floor tile applet to see that there are many types and characteristics of quadrilaterals including parallelograms, trapezoids,...