Instructional Video6:57
2
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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...
Lesson Plan
EngageNY

#### Triangle Congruency Proofs (part 2)

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

#### Triangle Congruency Proofs (part 1)

For Teachers 9th - 10th Standards
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...
Unit Plan
Mathematics Vision Project

#### Geometric Figures

For Teachers 10th - 12th Standards
Logical thinking is at the forefront of this jam-packed lesson, with young mathematicians not only investigating geometric concepts but also how they "know what they know". Through each activity and worksheet, learners wrestle with...
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...
Worksheet

#### Parallel Lines Proofs Practice

For Students 8th - 11th Standards
Here is a learning exercise that lines up perfectly with the skills needed to finish a geometric proof. Eleven problems are given to see if learners can prove that lines are parallel or angles are congruent.
Worksheet
Curated OER

#### Proofs Of The Pythagorean Theorem?

For Students 8th Standards
Even U.S. President James Garfield had his own proof of the Pythagorean Theorem! Pupils consider three different attempts at a geometric proof of the Pythagorean Theorem. They then select the best proof and write paragraphs detailing...
Instructional Video0:53
Corbett Maths

#### Angles in the Same Segment – Proof

For Students 8th - 12th Standards
If angles intercept the same arc, the angles must be the same size. The quick video talks through the proof of showing the reason two inscribed angles that intersect the same arc have the same measurement. Pupils then create their own...
Lesson Plan
EngageNY

#### Informal Proofs of Properties of Dilations

For Teachers 8th Standards
Challenge the class to prove that the dilation properties always hold. The lesson develops an informal proof of the properties of dilations through a discussion. Two of the proofs are verified with each class member performing the...
Lesson Plan
EngageNY

#### Informal Proof of the Pythagorean Theorem

For Students 8th Standards
Prove the Pythagorean Theorem using multiple informal proofs. Scholars first develop an understanding of the origins of the Pythagorean Theorem through proofs. They round out the lesson by using the theorem to find missing side lengths...
Unit Plan
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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...
Worksheet
Curated OER

#### Proofs

For Students 8th - 11th
In this geometric proof worksheet, students compose 20 triangle congruency proofs. Students will decide if there is enough information in problems 1-6 to prove if any triangles are congruent. In problems 17 to 20, students use given...
Worksheet
Geometry Accelerated

#### Accelerated Geometry Review Sheet

For Students 8th - 10th Standards
Your geometry learners use their knowledge of various geometric concepts to write proofs. Starting with givens containing parallel line segments with transversals and triangles and quadrilaterals, and the mid-point and distance formulas;...
Activity
1
1
Curated OER

#### Geometry Project

For Students 9th - 12th Standards
Proofs are usually an intimidating assignment. An engaging lesson focused on geometric proofs may reduce the anxiety! Pupils choose between several triangle proofs to complete and work on completing them. The assignment also gives a...
Unit Plan
Mathematics Vision Project

#### Congruence, Construction and Proof

For Teachers 9th - 10th Standards
Learn about constructing figures, proofs, and transformations. The seventh unit in a course of nine makes the connections between geometric constructions, congruence, and proofs. Scholars learn to construct special quadrilaterals,...
Unit Plan
Mathematics Vision Project

#### Module 2: Congruence, Construction and Proof

For Teachers 9th - 12th Standards
Construct yourself a winning geometry unit. A set of lessons introduces geometry scholars to constructions and proofs with compasses and straightedges. It also covers triangle congruence through transformations. This is the second of...
Handout
Shmoop

#### Coordinate Proofs

For Students 8th - 11th Standards
How do you know you know? Prove it! The guide goes through several examples and includes a link to a video to teach learners how to work through coordinate proofs. The goal is to prove that different shapes are indeed that shape.
Lesson Plan
1
1
Illustrative Mathematics

#### Similar Triangles

For Teachers 9th - 11th Standards
Proving triangles are similar is often an exercise in applying one of the many theorems young geometers memorize, like the AA similarity criteria. But proving that the criteria themselves are valid from basic principles is a great...
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...
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.
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...
Instructional Video22:15
2
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Flipped Math

#### Intro to Proofs

For Students 9th - 12th Standards
Prove the best way to keep up in Geometry. Scholars first review algebraic properties from Algebra. Learners then use the properties to create two-column proofs to solve linear equations before completing algebraic proofs by providing...