Curated OER
Babylonian Mathematics I
Learners examine a Babylonian clay tablet and the mathematics found on it as a catalyst to investigate a variety of mathematical ideas. They work with prime numbers, classify numbers as whole, integer, rational, or irrational and use...
Curated OER
The Truth About Triangles And Proofs
Students engage in a lesson that is about the classification of triangles and the mathematical proofs involved in working with them. They work on a variety of problems that are created by the teacher with the focus upon the importance of...
Curated OER
Pythagoras' Theorem
Students are introduced to the Pythagoras' Theorem and its history, proofs and practice in application. Students find perimeters, areas and volume of everyday objects. Students state and explain the theory.
Curated OER
The Proof of the Century!
Students do Web research in the field of mathematics. They explore mathematical proofs and apply them to the Pythagorean theorem. They also explore the general ideas of Fermat's Last Theorem
EngageNY
Base Angles of Isosceles Triangles
Build confidence in proofs by proving a known property. Pupils explore two approaches to proving base angles of isosceles triangles are congruent: transformations and SAS. They then apply their understanding of the proof to more complex...
EngageNY
The Graph of a Linear Equation in Two Variables Is a Line
Show your class that linear equations produce graphs of lines. The 20th segment in a unit of 33 provides proof that the graph of a two-variable linear equation is a line. Scholars graph linear equations using two points, either from...
Curated OER
Proofs of the Pythagorean Theorem
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...
Chapman University
Proof of L’Hospital’s Rule
Understanding how calculus formulas were derived connects learners to the idea that the study of mathematics is continuous and cumulative. Learners will also develop a deeper appreciation for the derivative's application in simplifying...
EngageNY
End-of-Module Assessment Task: Grade 8 Mathematics (Module 7)
It's time to discover what your classes have learned! The final lesson in the 25-part module is an assessment that covers the Pythagorean Theorem. Application of the theorem includes distance between points, the volume of...
Curated OER
Logic and Proof Writing
Young scholars define inductive and deductive reasoning and write two column proofs. In this geometry lesson, students analyze arguments and draw conclusion. They define steps necessary to arrive at the correct answer when completing...
Mathematics Vision Project
Module 3: Geometric Figures
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.
Curated OER
Mathematical Proofs
Students explore the nature of mathematical proofs and mathematical inquiry. They complete the activity "Using the Pythagorean Theorem". They read selected articles and participate in class discussions.
Curated OER
Geometry Project
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...
Education Development Center
Sum of Rational and Irrational is Irrational
Sometimes the indirect path is best. Scholars determine whether the sum of a rational number and an irrational number is irrational. Reading a transcript of a conversation between classmates leads to an indirect proof of this concept.
Illustrative Mathematics
Shortest Line Segment from a Point P to a Line L
One of the hardest skills for many young geometers to grasp is to move beyond just declaring obvious things true, and really returning to fundamental principles for proof. This brief exercise stretches those proving muscles as the class...
Illustrative Mathematics
Similar Triangles
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...
Illustrative Mathematics
Right Triangles Inscribed in Circles II
So many times the characteristics of triangles are presented as a vocabulary-type of activity, but in this activity they are key to unraveling a proof. A unique attack on proving that an inscribed angle that subtends a diameter must be a...
Virginia Department of Education
Congruent Triangles
Is this enough to show the two triangles are congruent? Small groups work through different combinations of constructing triangles from congruent parts to determine which combinations create only congruent triangles. Participants use the...
Illustrative Mathematics
Equal Area Triangles on the Same Base II
A deceptively simple question setup leads to a number of attack methods and a surprisingly sophisticated solution set in this open-ended problem. Young geometers of different strengths can go about defining the solutions graphically,...
Shodor Education Foundation
Squaring the Triangle
Teach budding mathematicians how to square a triangle with an interactive that shows a graphical proof of the Pythagorean Theorem. Pupils alter the lengths of the legs using sliders. Using the inputted lengths, the applet displays the...
Chapman University
A Pythagorean-Style Proof of the Sine Sum-of-Angles Formula
This well organized poster shows a step-by-step algebraic proof and related graphic. Understanding how formulas were derived, connects learners to the idea that the study of mathematics is continuous and cumulative. Learners will also...
Curated OER
Inductive vs. Deductive Proof
Twelfth graders differentiate between inductive and deductive proofs. In this differentiating between inductive and deductive proofs lesson, 12th graders compare strengths and weaknesses of each type of proof. Students discuss an...
Curated OER
Using Proof in Algebra
In this using proofs in algebra activity, 10th graders solve 2 proofs by applying the many rules from algebra for the Properties of Equality for real numbers. They name the property that justifies each statement as seen in the...
Curated OER
Discovering Math: Concepts in Geometry
Middle and high schoolers explore the concept of proving the Pythagorean Theorem. They research proofs of the Pythagorean Theorem. Pupils create posters of proofs, and research Greek mathematicians.