EngageNY
How Far Away Is the Moon?
Does the space shuttle have an odometer? Maybe, but all that is needed to determine the distance to the moon is a little geometry! The lesson asks scholars to sketch the relationship of the Earth and moon using shadows of an eclipse....
Curated OER
Geo Jammin' By DeSign - Day 1, Lesson 2: Dancing Duo
Second graders and teachers identify geometric vocabulary word by searching a geometry website. They create a Quilt Word Wall using the geometry words.
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Parallel and Perpendicular Lines
Use what you know about parallel and perpendicular lines to write equations! Learners take an equation of a line and write an equation of a line that is parallel or perpendicular using slope criteria. They then solve problems to...
EngageNY
Perimeter and Area of Triangles in the Cartesian Plane
Pupils figure out how to be resourceful when tasked with finding the area of a triangle knowing nothing but its endpoints. Beginning by exploring and decomposing a triangle, learners find the perimeter and area of a triangle. They then...
Curated OER
Finite Geometry
Young scholars solve for the area and perimeter of polygons. In this geometry lesson, students identify repeated patterns and create formula to solve problems. They make conjectures and prove hypotheses.
Curated OER
Investigating Shapes in Our World
First graders explore shapes. In this geometry lesson, 1st graders make shapes with geo-boards, use play-dough to make three-dimensional figures, and make a shape book using pre-cut shapes.
Curated OER
Geo-Critters (Geometry Critters)
Students read the book The Math Curse by Jon Scieszka and study geometry. In this geometry lesson, students identify geometric shapes and their properties. Students create a geo-critter.
Curated OER
Geo Jammin' - Day 4, Lesson 12: Geo Gee-Hawin'
Students review geometry unit content through a vocabulary/word game. They demonstrate understanding using geoboards to answer questions. They work in groups and it's a race to the correct answer.
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Searching a Region in the Plane
Programming a robot is a mathematical task! The activity asks learners to examine the process of programming a robot to vacuum a room. They use a coordinate plane to model the room, write equations to represent movement, determine the...
Curated OER
Plane Figures
Fifth graders create polygons requested by their teacher. In this polygons lesson, 5th graders watch a video and listen to a song about polygons. Then, students take turns labeling various polygons and practice making polygons.
Curated OER
Geo Jammin' - Day 6, Lesson 20: Hail, Hail, the Gang's All Here
Young scholars use shape puppets to review geometry content. They take turns singing songs, reading students poems, reciting class bulletin board notes and choral poems. They prepare for their summative assessments through play and...
EngageNY
Triangle Congruency Proofs (part 1)
Can they put it all together? Ninth graders apply what they know about proofs and triangle congruence to complete these proofs. These proofs go beyond the basic triangle congruence proofs and use various properties, theorems, and...
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Special Relationships Within Right Triangles—Dividing into Two Similar Sub-Triangles
Why are right triangles so special? Pupils begin their study of right triangles by examining similar right triangles. Verifying through proofs, scholars recognize the three similar right triangles formed by drawing the altitude. Once...
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Triangle Congruency Proofs (part 2)
Looking to challenge your students that have mastered basic triangle congruence proofs? A collection of proofs employ previously learned definitions, theorems, and properties. Pupils draw on their past experiences with proofs to...
EngageNY
Similarity and the Angle Bisector Theorem
Identifying and verifying reproducible patterns in mathematics is an essential skill. Mathematicians identify the relationship of sides when an angle is bisected in a triangle. Once the pupils determine the relationship, they prove it to...
EngageNY
Multiplying and Dividing Expressions with Radicals
That's radical! Simplifying radicals may not be exciting, but it is an important skill. A math lesson provides explanations of properties used throughout the material. Scholars practice skills needed to multiply and divide radical...
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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 polygons.
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Using Trigonometry to Determine Area
What do you do when you don't think you have enough information? You look for another way to do the problem! Pupils combine what they know about finding the area of a triangle and trigonometry to determine triangle area when they don't...
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Equations for Lines Using Normal Segments
Describing a line using an algebraic equation is an essential skill in mathematics. The previous activity in the series challenged learners to determine if segments are perpendicular with a formula. Now they use the formula to determine...
EngageNY
Congruence Criteria for Triangles—SAS
Looking for a different approach to triangle congruence criteria? Employ transformations to determine congruent triangles. Learners list the transformations required to map one triangle to the next. They learn to identify congruence if...
EngageNY
Applications of Congruence in Terms of Rigid Motions
Corresponding parts, congruent parts, congruent corresponding parts—what does it all mean? The resource challenges pupils to identify corresponding parts for pairs of figures. It uses examples of figures that undergo rigid...
Curated OER
Menelaus' Theorem
Students investigate Menelaus Theorem. In this geometry instructional activity, students calculate the area of polygons. They differentiate between boundaries point, interior points and area of lattice points.
Curated OER
Pedal Triangles
Students identify the properties and theorems of triangles. In this geometry lesson, students construct angle bisectors using a compass and straight edge. They identify triangular similarity and congruency.
Curated OER
Ceva’s Theorem
Students prove and use Ceva's Theorem to solve problems. In this geometry lesson, students analyze polygons for patterns and calculate the area of each shape. They relate polygons to the real world.