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Worksheet
Mt. San Antonio Collage

The Trapezoid

For Students 9th - 12th Standards
Enjoy this nicely organized worksheet that puts together multiple problems regarding trapezoid proofs. The resource can be used as a guide that begins with proving properties and ends with solving for measures of line segments.
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Worksheet
Mt. San Antonio Collage

Inequalities in a Triangle

For Students 9th - 12th Standards
Stuck with triangle proofs? Take a 180° and provide learners with a guided worksheet that tests their knowledge with triangle inequalities. The questions require different types of proofs that range in levels of difficulty. 
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Handout
El Paso Community College

Geometry Definitions

For Students 7th - 9th Standards
Geometry is full of shapes, figures, and corresponding things here and there. The guide shares all of the key pieces of geometric information in a nicely color-coded and labeled sheet. 
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Handout
Lockport City School District

Reasons for Geometric Statement/Reason Proofs

For Students 8th - 11th Standards
Stuck trying to remember the formal language of a geometric proof? Never fear, this handout has them all ready to go. The reasons are sectioned by topic so this handy guide is ready when you are to tackle those two column proofs. 
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Unit Plan
1
1
EngageNY

Congruence, Proof, and Constructions

For Teachers 8th - 10th Standards
This amazingly extensive unit covers a wealth of geometric ground, ranging from constructions to angle properties, triangle theorems, rigid transformations, and fundamentals of formal proofs.  Each of the almost-forty lessons is broken...
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Instructional Video5:42
2
2
Flipped Math

Unit 3 Review: Parallell and Perpendicular Lines

For Students 9th - 12th Standards
Learners watch a quick review on the Parallel and Perpendicular Lines unit. The pupils work through ten review problems ranging from identifying types of angles formed by parallel lines and transversals to writing equations of parallel...
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Instructional Video9:36
2
2
Flipped Math

Proving Lines Parallel

For Students 9th - 12th Standards
Show it can all be proved. Scholars learn the converses of the properties of parallel lines. Using the converses, pupils determine which lines are parallel based on angle measurements and practice using a flow proof to show that two...
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Instructional Video12:02
2
2
Flipped Math

Properties of Parallel Lines

For Students 9th - 12th Standards
Work within a parallel universe. Scholars learn about the relationships of angles when two parallel lines are intersected by a transversal. They see how to find the measurements of all eight angles by knowing the measure of one angle....
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Instructional Video6:57
2
2
Flipped Math

Unit 2 Review: Reasoning and Proofs

For Students 9th - 12th Standards
The proof is in the review. Individuals watch a short review of the content from the unit to prepare for the unit exam. The review covers inductive reasoning, conditional and related statements, and two-column algebraic and geometric...
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Instructional Video16:33
2
2
Flipped Math

More with Proofs

For Students 9th - 12th Standards
Proofs may be as easy as 1, 2, 3 ... maybe. Pupils participate in creating four example proofs. The presentation uses a list of geometric properties to develop the proofs by filling in both the statements and reasons. Scholars practice...
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Instructional Video14:29
2
2
Flipped Math

Addition Postulate

For Students 9th - 12th Standards
Add a little algebra to the geometry. Class members learn about the Addition Postulate for segments and angles. The pupils use their knowledge of solving equations to find lengths of segments and measures of angles. Individuals apply...
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Instructional Video19:36
2
2
Flipped Math

Angle Pairs

For Students 9th - 12th Standards
Complement the class by identifying pairs of angles. With a vocabulary lesson, pupils learn the names and definitions of special angle pairs including adjacent, vertical, complementary, supplementary, and linear pairs. Using the...
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Performance
Radford University

Parallel Lines Task

For Teachers 9th - 12th Standards
Transform the classroom into a coordinate plane. Scholars walk along parallel lines drawn on a coordinate plane on the classroom floor. They measure angles and slopes and use the results to develop criteria that would make the lines...
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Unit Plan
Radford University

Parallel Lines Cut By a Transversal

For Teachers 9th - 12th Standards
Perhaps planning a city isn't so difficult after all. Scholars first perform geometric constructions and investigate how parallel lines are useful in real-world situations. They then work on a city design project, drawing street maps,...
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Unit Plan
Radford University

Parallel Lines Cut by a Transversal

For Teachers 9th - 12th Standards
Use the parallel lines to find your way. After first reviewing geometric constructions and the relationships between angles formed by parallel lines and a transversal, young mathematicians write proofs for theorems relating to parallel...
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Unit Plan
Radford University

Real Life Parallels

For Teachers 9th - 12th Standards
There's no parallel to a great resource. Scholars take part in three lessons in which they investigate parallel lines in real-world situations. They search for and take pictures of parallel lines in and around the school, develop artwork...
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Assessment
1
1
CCSS Math Activities

Smarter Balanced Sample Items: High School Math – Claim 3

For Teachers 9th - 12th Standards
Communication is the key. A presentation provides 25 sample items for Claim 3, Communicating Reasoning, for the Smarter Balanced High School Math assessment. Items require pupils to answer the question and provide logical reasoning to...
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Unit Plan
Mathematics Vision Project

Module 3: Geometric Figures

For Teachers 9th - 12th Standards
It's just not enough to know that something is true. Part of a MVP Geometry unit teaches young mathematicians how to write flow proofs and two-column proofs for conjectures involving lines, angles, and triangles.
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Activity
National Council of Teachers of Mathematics

Bank Shot

For Teachers 9th - 12th Standards
Bank on geometry to line up the shot. The resource asks the class to determine the location to bank a cue ball in a game of billiards. Using their knowledge, class members determine where to hit the bumper to make a shot and discuss...
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Interactive
1
1
GeoGebra

Conjectures and Proof

For Students 9th - 12th Standards
Transform proofs using triangle rotations. By rotating a triangle around various points, class members develop proofs. Participants prove relationships of alternative interior angles formed by parallel lines and the sum of the interior...
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Interactive
CK-12 Foundation

Identify Line Types: Intersecting and Parallel Lines

For Students 6th Standards
Navigate your way through a lesson on types of lines. Individuals drag line segments to illustrate paths between pairs of houses on an interactive map. They determine if these line segment pairs are intersecting or parallel.
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Interactive
CK-12 Foundation

Identify Line Types: Identify Types of Lines

For Students 6th - 12th Standards
If lines aren't parallel or perpendicular, then what are they? An interactive lets users rotate a line to change its orientation with respect to another line. It then indicates whether the lines are parallel, perpendicular, or...
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Activity
Education Development Center

Proof with Parallelogram Vertices

For Teachers 8th - 10th Standards
Geometric figures are perfect to use for proofs. Scholars prove conjectures about whether given points lie on a triangle and about midpoints. They use a provided dialogue among fictional students to frame their responses.
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Lesson Plan
Virginia Department of Education

Lines and Angles

For Teachers 9th - 11th Standards
Explore angle relationships associated with transversals. Pupils construct parallel lines with a transversal and find the measures of the angles formed. They figure out how the different angles are related before constructing...