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Lesson Plan
EngageNY

Thales’ Theorem

For Teachers 9th - 10th Standards
Isn't paper pushing supposed to be boring? Learners attempt a paper-pushing puzzle to develop ideas about angles inscribed on a diameter of a circle. Learners then formalize Thales' theorem and use geometric properties to develop a proof...
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Lesson Plan
West Contra Costa Unified School District

Pythagorean Theorem and Its Converse

For Teachers 9th - 12th Standards
Challenge scholars to prove the Pythagorean Theorem geometrically by using a cut-and-paste activity. They then must solve for the missing sides of right triangles.
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Lesson Plan
EngageNY

Analytic Proofs of Theorems Previously Proved by Synthetic Means

For Students 9th - 12th Standards
Prove theorems through an analysis. Learners find the midpoint of each side of a triangle, draw the medians, and find the centroid. They then examine the location of the centroid on each median discovering there is a 1:2 relationship....
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Lesson Plan
Curated OER

Worksheet 5: Property Limits and the Squeeze Theorem

For Teachers 12th - Higher Ed
In this math worksheet, students answer 6 questions regarding given limits in a table of data, properties of limits and the Squeeze Theorem.
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Lesson Plan
Curated OER

Hey, Pythagoras! Help Me Understand Your Theorem!

For Teachers 8th - 12th
Learners explore the Pythagorean Theorem. For this math lesson, pupils solve problems using the Pythagorean Theorem. They select the appropriate numbers to substitute in the formula to solve problems.
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Lesson Plan
EngageNY

Prove the Pythagorean Theorem Using Similarity

For Students 9th - 10th Standards
Amaze your classes with the ability to find side lengths of triangles immediately — they'll all want to know your trick! Learners use the Pythagorean Theorem and special right triangle relationships to find missing side lengths.
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Lesson Plan
EngageNY

Pythagorean Theorem, Revisited

For Students 8th Standards
Transform your pupils into mathematicians as they learn to prove the popular Pythagorean Theorem. The 16th lesson in the series of 25 continues by teaching learners how to develop a proof. It shows how to prove the Pythagorean Theorem...
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Handout
Charleston School District

Pythagorean Theorem and Converse

For Students 8th Standards
You've heard that it is true, but can you prove it? Scholars learn the Pythagorean Theorem through proof. After an overview of proofs of the theorem, learners apply it to prove triangles are right and to problem solve. This is the second...
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Lesson Plan
EngageNY

Ptolemy's Theorem

For Teachers 9th - 12th Standards
Everyone's heard of Pythagoras, but who's Ptolemy? Learners test Ptolemy's Theorem using a specific cyclic quadrilateral and a ruler in the 22nd installment of a 23-part module. They then work through a proof of the theorem.
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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...
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Lesson Plan
EngageNY

Converse of the Pythagorean Theorem

For Students 8th Standards
Discover a new application of the Pythagorean Theorem. Learners prove and apply the converse of the Pythagorean Theorem in the 17th lesson in a 25-part series. The examples ask learners to verify right triangles using the converse of the...
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Lesson Plan
Curated OER

Proving (a Theorem) and Disproving (a Theory)

For Teachers 7th - 12th
As a cross-curricular lesson, your class examines the issues of gender discrimination, careers, and gender roles. They read and discuss an article, prepare a proof of the Pythagorean theorem as a class, and develop a creative...
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Lesson Plan
EngageNY

Inscribed Angle Theorem and Its Applications

For Teachers 9th - 10th Standards
Inscribed angles are central to the lesson. Young mathematicians build upon concepts learned in the previous lesson and formalize the Inscribed Angle Theorem relating inscribed and central angles. The lesson then guides learners to prove...
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Printables
Mr. Williams Maths

Eight Circle Theorems Page

For Teachers 8th - 12th Standards
Your learners will find these circle theorems nicely organized with diagrams included that present the geometric relationships between the circle circumference, chords, central and circumference angles and tangents.
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Lesson Plan
Curated OER

The Pythagorean Theorem Lesson 2

For Teachers 8th - 12th
Learners discuss and review examples of the Pythagorean Theorem using a GSP, Geometer's Sketchpad, activity.
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Lesson Plan
Curated OER

Worksheet 5 - Squeeze Theorem

For Teachers Higher Ed
In this Squeeze Theorem worksheet, students compute limits, identify a graph that represents the Squeeze Theorem, and graph given functions. This two-page worksheet contains seven multi-step problems.
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Lesson Plan
Curated OER

Proofs of the Pythagorean Theorem

For Teachers 9th - 12th Standards
Working individually and collaboratively, geometers gain a clear understanding of the Pythagorean theorem. They create, explain, and compare proofs of the theorem. Proofs involve areas of trapezoids, squares, and triangles, congruent...
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Lesson Plan
EngageNY

Trigonometry and the Pythagorean Theorem

For Students 9th - 11th Standards
Ancient Egyptians sure knew their trigonometry! Pupils learn how the pyramid architects applied right triangle trigonometry. When comparing the Pythagorean theorem to the trigonometric ratios, they learn an important connection that...
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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...
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Lesson Plan
Curated OER

Euclidean Direct Proofs

For Teachers 9th - 10th
Learning how to prove theorems in geometry can be challenging. This resource explains what a proof is, and the different styles for proofs. It also contains links to web-based practice problems that help guide learners though example...
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Lesson Plan
Curated OER

The First Fundamental Theorem of Calculus

For Teachers 9th - 12th Standards
Solve problems using the fundamental theorem. In this calculus lesson, high schoolers solve problems using theorems and proving theorems. They derive the fundamental theorem as they study it.
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Lesson Plan
EngageNY

Congruence Criteria for Triangles—AAS and HL

For Students 9th - 10th Standards
How can you prove it? Guide classes through an exploration of two possible triangle congruence criteria: AAS and HL. Learners connect this criteria to those previous learned and also explore criteria that does not work. The lesson...
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Instructional Video9:36
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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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Worksheet
Curated OER

Pythagorean Theorem

For Students 10th
In this Pythagorean Theorem worksheet, 10th graders solve and complete 19 various types of problems. First, they draw the square shown and divide its sections as shown. Then, students cut out the 6 parts of the square and rearrange the 4...