EngageNY
Triangle Congruency Proofs (part 2)
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...
EngageNY
Triangle Congruency Proofs (part 1)
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...
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...
Curated OER
Four Algebraic Proof Charts
In this proof chart worksheet, students are given an equation and asked to solve for the unknown and to justify the steps by filling in the proof using math properties. The worksheet contains four problems presented as proof charts.
EngageNY
Properties of Parallelograms
Everyone knows that opposite sides of a parallelogram are congruent, but can you prove it? Challenge pupils to use triangle congruence to prove properties of quadrilaterals. Learners complete formal two-column proofs before moving on to...
EngageNY
Unknown Angle Proofs—Proofs of Known Facts
Lead the class in a Greek history activity with a geometric twist. Pupils relate a short video about geometric properties to modern-day methods of solving for unknown angles. They discuss parallel line theorems and complete practice...
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,...
EngageNY
The Converse of the Pythagorean Theorem
Is it a right triangle or not? Introduce scholars to the converse of the Pythagorean Theorem with a lesson that also provides a proof by contradiction of the converse. Pupils use the converse to determine whether triangles with given...
Old Dominion University
Introduction to Calculus
This heady calculus text covers the subjects of differential and integral calculus with rigorous detail, culminating in a chapter of physics and engineering applications. A particular emphasis on classic proof meshes with modern graphs,...
Curated OER
Easy Worksheet: Congruent Segments
In this congruent segments worksheet, students solve 6 short answer problems. Students justify steps in a proof by identifying the reason for various steps. Students justify steps of proofs using the transitive property, congruent...
Curated OER
NON-EUCLIDEAN GEOMETRY.
Students study relationships between angles, side lengths, perimeters, areas and volumes of similar objects. In this lesson students also create and critique inductive and deductive arguments concerning congruency, similarity and the...
Curated OER
Solving Equations
In this Algebra I worksheet, 9th graders solve basic equations, writng a proof of the solution and justifying each step. The one page worksheet contains four questions. Answers are not included.
EngageNY
Review of the Assumptions (part 1)
What was the property again? Tired of hearing this from your pupils? Use this table to organize properties studied and as a reference tool for individuals. Learners apply each property in the third column of the table to ensure their...
Curated OER
Pythagorean Theorem by Graphic Manipulation
There are many different ways to show a proof of the Pythagorean Theorem. Here is a nice hands-on paper cutting activity that shows a graphic representation. You can even challenge your young Pythagoreans to come up with their own...
Curated OER
Mathematics
Twelfth graders explore a variation of proof. In this geometry lesson, 12th graders apply their knowledge of proof to different scenario. They use 3 different tiers to advance through the lesson.
Curated OER
Around the World With Geometry
Learners identify shapes, create shapes, and make a pyramid, a drum, and a sail using their shapes. In this shapes lesson plan, students also identify plane and space shapes.
Curated OER
Triangles
In this geometry worksheet, 10th graders solve problems involving triangular inequality. They apply the proofs and theorem of triangles to solve these problems. There is an overview and one question.
Curated OER
Why Doesn't SSA Work?
Students investigate the relationship between angles and their sides. In this geometry lesson, students prove why SSA does not work as a true angle side relationship theorem.
EngageNY
Three-Dimensional Space
How do 2-D properties relate in 3-D? Lead the class in a discussion on how to draw and see relationships of lines and planes in three dimensions. The ability to see these relationships is critical to the further study of volume and other...
Curated OER
Write the Counterexample
In this counterexample worksheet, students provide counterexamples for the four given statements. The solutions are not provided.
NASA
Pop! Rockets
Off they go — launching rockets is fun. The lesson plan contains templates to build paper rockets that can be launched from a PVC pipe launcher. Individuals or groups build the rockets and determine the shapes for their fins. Included...
Virginia Department of Education
Logic and Conditional Statements
If there is a conditional statement, then there is a hypothesis and conclusion. Pupils learn how to identify the parts of conditional statements. Class members continue to work with conditional statements and rewrite them in their many...
Shodor Education Foundation
Surface Area of Rectangular Prism
With this interactive lesson plan, learners compute the surface area of rectangular prisms. They visit an online investigation applet and record data on the provided handout. Pair this lesson plan with the volume lesson plan by the same...
Curated OER
Interactivate - Lines, Rays, Line Segments, and Planes
Students explore lines, rays, line segments, and planes. In this math lesson, students discuss the math concepts and direct their instructor in graphing functions. Students collaborate in graphing additional functions.