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Lesson Plan
EngageNY

Unknown Angle Proofs—Proofs with Constructions

For Teachers 9th - 10th Standards
Provide your emerging mathematicians with the tools to learn as they incorporate auxiliary lines to solve unknown angle proofs in this continuing segment. They decipher information from a diagram to uncover the missing pieces and...
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Lesson Plan
Curated OER

Angle Action 1,2 and 3

For Teachers 8th - 10th
Students investigate angles through construction. In this geometry lesson, students use a protractor to identify the measurement of an angle. They identify angles cut by a transversal and two parallel lines.
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Lesson Plan
Curated OER

Transverse Wave Demonstrator

For Teachers 11th - 12th
Students discover the properties of waves in Chemistry and Physics. In groups, they develop and build their own device to demonstrate transverse waves. They complete their tests, record the results and discuss the conclusions with the...
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Lesson Plan
Curated OER

Side Splitter Triangles

For Teachers 8th - 11th
Students investigate the side splitter theorem. In this geometry lesson, students estimate and solve problems dealing with ratios and proportions. They identify angles created by lines that are parallel.
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Lesson Plan
Mathematics Assessment Project

Identifying Similar Triangles

For Teachers 7th - 9th Standards
Math whizzes work with angle sums and exterior angles to figure out the measure of other angles. This particular publication provides comprehensive support in the form of an anticipatory activity, questions designed to prompt discussion,...
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Lesson Plan
EngageNY

Informal Proof of AA Criterion for Similarity

For Teachers 8th Standards
What does it take to show two triangles are similar? The 11th segment in a series of 16 introduces the AA Criterion for Similarity. A discussion provides an informal proof of the theorem. Exercises and problems require scholars to apply...
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Lesson Plan
Curated OER

Constructing Midsegments of Triangles

For Teachers 9th - 10th
Students construct midsegments. In this geometry lesson, students make conjectures and apply properties of triangles to solve problems. They complete an activity on the computer.
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Lesson Plan
EngageNY

Similarity and the Angle Bisector Theorem

For Teachers 9th - 10th Standards
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...
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Worksheet
Curated OER

Logical Relationship of Postulates & Theorems

For Students 10th - 12th
In this postulates and theorems worksheet, students explore a concept map containing information about angles and sides, alternate interior angles, and diagonals of a parallelogram.  They use the concept map to prove theorems...
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Lesson Plan
EngageNY

Congruence Criteria for Triangles—SAS

For Students 9th - 10th Standards
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...
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Lesson Plan
EngageNY

More About Similar Triangles

For Teachers 8th Standards
Determine whether two triangles are similar. The lesson presents opportunities for pupils to find the criterion needed to show that two triangles are similar. Scholars use the definition of similarity to find any missing side...
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Lesson Plan
Curated OER

Strongest Polygon

For Teachers 9th - 12th
Students define and identify shapes by name. In this geometry lesson, students construct, identify and compare polygons based on the number of sides. They classify each shape based on their angle sum theorem.
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Lesson Plan
Curated OER

Incredible Edible Bridges

For Teachers 7th - 10th
Students create a bridge using engineering and geometric concepts. In this geometry instructional activity, students identify the missing measures of polygons sides and angles. They work together to solve real life situation using...
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Activity
Texas Instruments

Texas Instruments: Parallel Lines Cut by a Transversal With Cabri Jr.

For Teachers 9th - 10th
Using Cabri Jr, the students (with the teachers help) will create parallel lines cut by a transversal, measure angles, and compare the relationships of the angles formed using features of the Cabri Jr.
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Unit Plan
CK-12 Foundation

Ck 12: Elem Math: Visually Evaluating Parallel Lines Cut by a Traversal

For Students 2nd - 4th Standards
[Free Registration/Login may be required to access all resource tools.] Students watch a video and attempt practice problems about parallel lines cut by a transversal.
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Activity
Texas Instruments

Texas Instruments: Parallel Lines Cut by a Transversal

For Teachers 9th - 10th
In this activity, students learn and increase their knowledge about the angles formed when parallel lines are cut by a transversal.
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Activity
Texas Instruments

Texas Instruments: Properties of Parallel Lines Cut by a Transversal

For Teachers 9th - 10th
In this activity, students create parallel lines and a transversal, and study the properties of the lines and their angles.
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Unit Plan
Texas Education Agency

Texas Gateway: Making Conjectures About Parallel and Perpendicular Lines

For Students 9th - 10th Standards
The student will verify theorems about angles formed by parallel lines cut by a transversal and apply these relationships to solve problems.
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Unit Plan
CK-12 Foundation

Ck 12: Geometry: Parallel Lines and Transversals

For Students 9th - 10th Standards
[Free Registration/Login may be required to access all resource tools.] Apply the fact that transversals cut parallel lines proportionally.
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Activity
Texas Instruments

Texas Instruments: Parallel Lines

For Teachers 9th - 10th
This file contains questions related to parallel lines cut by a transversal and the angles formed. The questions can be used to asses your students' understanding of this topic in geometry.
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Handout
Sonoma State University

Sonoma State University: Parallel Lines and Similar and Congruent Triangles

For Students 9th - 10th Standards
This site defines parallel lines, parallel lines cut by a transverse, and congruent triangles. It also contains links for related terms.
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Activity
Texas Instruments

Texas Instruments: Sail Problem (Parallel Lines & Segment Relationships)

For Teachers 9th - 10th
In this activity, students will explore the proportional relationships involved in multiple parallel lines being cut by transversals. These relationships are approached through exploration of a sail design problem, where students are to...
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Lesson Plan
PBS

Pbs Learning Media: Lines and Angles: Targeted Math Instruction

For Teachers 9th - 10th Standards
At the end of this lesson, students will be able to identify and apply the properties of lines and angles and understand the concept of parallel, perpendicular, complementary and supplementary angles, vertical angles, and parallel lines...
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Unit Plan
Texas Education Agency

Texas Gateway: Making and Verifying Conjectures About Angles

For Students 9th - 10th
Given the relationship(s) among a set of angles, the student investigates the patterns and makes conjectures about the geometric relationships, including angles formed by parallel lines cut by a transversal.