Curated OER
Fractals and the Chaos Game
Students explore the concept of fractals. In this fractals lesson, students play the "Chaos Game" via an applet. Students place dots on the screen to recognize that they have created Sierpinski's Triangle.
Curated OER
Geometry and Shapes in the X-36
Students describe, draw, and classify shapes. They use the internet to research the X-36 aircraft. Students identify the geometric shapes in the aircraft. They calculate the number of sides in an x-36.
Curated OER
Geometry of Radio Meteor Reflections
Ninth graders investigate and describe ways that human understanding of Earth and space has depended on technological development. They describe and interpret the science of optical and radio telescopes, space probes and remote sensing...
Curated OER
Quilt Geometry
Seventh graders explore lines of symmetry, congruent polygons and patterns. They listen to "The Seasons Sewn," observe a PowerPoint presentation, and identify congruent polygons and visual patterns. Through an internet activity, 7th...
Curated OER
Algebraic Processes And Its Connection To Geometry
Students investigate the concept of polygons using a variety of activities. They explore the vocabulary of polygons by constructing a graphic organizer. Then students categorize the characteristics of several polygons and contribute the...
Curated OER
Symmetry in Kaleidoscope Designs
Students define reflection, rotation and symmetry. In this symmetry instructional activity, students move the graph around the coordinate plane and identify the line of symmetry. They identify the different designs of a kaleidoscope.
Curated OER
Mathematics Witing: Algebraic Processes and Its Connections to Geometry
Students, using manipulatives, determine how many different ways there are to arrange 3 and 4 objects. They organize and record their arrangements. Students investigate the pattern generated by 3 and 4 objects, they predict how many ways...
EngageNY
The Volume of Prisms and Cylinders and Cavalieri’s Principle
Young mathematicians examine area of different figures with the same cross-sectional lengths and work up to volumes of 3D figures with the same cross-sectional areas. The instruction and the exercises stress that the two...
EngageNY
How Do Dilations Map Angles?
The key to understanding is making connections. Scholars explore angle dilations using properties of parallel lines. At completion, pupils prove that angles of a dilation preserve their original measure.
EngageNY
Construct an Equilateral Triangle (part 2)
Triangles, triangles, and more triangles! In this second installment of a 36-part series, your young mathematicians explore two increasingly challenging constructions, requiring them to develop a way to construct three triangles that...
EngageNY
Properties of Parallelograms
Everyone knows that opposite sides of a parallelogram are congruent, but can you prove it? Challenge pupils to use triangle congruence to prove properties of quadrilaterals. Learners complete formal two-column proofs before moving on to...
EngageNY
Dilations from Different Centers
Can you follow a composition of transformations, or better yet construct them? Young mathematicians analyze the composition of dilations, examining both the scale factor and centers of dilations. They discover relationships for both...
EngageNY
What Are Similarity Transformations, and Why Do We Need Them?
It's time for your young artists to shine! Learners examine images to determine possible similarity transformations. They then provide a sequence of transformations that map one image to the next, or give an explanation why it is...
EngageNY
The Angle-Angle (AA) Criterion for Two Triangles to Be Similar
What do you need to prove triangles are similar? Learners answer this question through a construction exploration. Once they establish the criteria, they use the congruence and proportionality properties of similar objects to find...
EngageNY
Using Trigonometry to Find Side Lengths of an Acute Triangle
Not all triangles are right! Pupils learn to tackle non-right triangles using the Law of Sines and Law of Cosines. After using the two laws, they then apply them to word problems.
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Translations
Learn through constructions! Learners examine a translation using constructions and define the translation using a vector. Pupils then construct parallel lines to determine the location of a translated image and use the vector as a guide.
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Points of Concurrencies
You say that perpendicular bisectors intersect at a point? I concur! Learners investigate points of concurrencies, specifically, circumcenters and incenters, by constructing perpendicular and angle bisectors of various triangles.
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Three-Dimensional Space
How do 2-D properties relate in 3-D? Lead the class in a discussion on how to draw and see relationships of lines and planes in three dimensions. The ability to see these relationships is critical to the further study of volume and...
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Making Scale Drawings Using the Parallel Method
How many ways can you create a dilation? Many! Individuals strengthen their understanding of dilations by using various methods to create them. The new technique builds on pupils' understanding of the ratio method. Using the ratio,...
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Review of the Assumptions (part 1)
What was the property again? Tired of hearing this from your pupils? Use this table to organize properties studied and as a reference tool for individuals. Learners apply each property in the third column of the table to ensure their...
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...
EngageNY
Dilations as Transformations of the Plane
Compare and contrast the four types of transformations through constructions! Individuals are expected to construct the each of the different transformations. Although meant for a review, these examples are excellent for initial...
EngageNY
How Do Dilations Map Segments?
Do you view proofs as an essential geometric skill? The resource builds on an understanding of dilations by proving the Dilation Theorem of Segments. Pupils learn to question and verify rather than make assumptions.
EngageNY
Adding and Subtracting Expressions with Radicals
I can multiply, so why can't I add these radicals? Mathematicians use the distributive property to explain addition of radical expressions. As they learn how to add radicals, they then apply that concept to find the perimeter of...