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...
EngageNY
Informal Proofs of Properties of Dilations
Challenge the class to prove that the dilation properties always hold. The activity develops an informal proof of the properties of dilations through a discussion. Two of the proofs are verified with each class member performing the...
EngageNY
Congruence, Proof, and Constructions
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...
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...
EngageNY
Unknown Angle Proofs—Proofs of Known Facts
Lead the class in a Greek history lesson plan 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...
CK-12 Foundation
Proofs: Angle Pairs and Segments—The Three Angle Problem
Finding the sum of the measures of three angles is easy, unless you have no clue what the measures are. Learners use an interactive diagram to see a geometric problem in a different way. A set of challenge questions takes them through...
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
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...
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,...
EngageNY
Converse of the Pythagorean Theorem
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...
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...
Radford University
Parallel Lines, Transversals, and Angles: What’s the Connection?
Streets, bridges, and intersections, oh my! Parallel lines and transversals are a present in the world around us. Learners begin by discovering the relationship of the angles formed by parallel lines and a transversal. They then apply...
Inside Mathematics
Magic Squares
Prompt scholars to complete a magic square using only variables. Then they can attempt to solve a numerical magic square using algebra.
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...
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
Around the World With Geometry
Students 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
Interactivate - Lines, Rays, Line Segments, and Planes
Students explore lines, rays, line segments, and planes. In this math lesson plan, students discuss the math concepts and direct their instructor in graphing functions. Students collaborate in graphing additional functions.
Shodor Education Foundation
Surface Area of Rectangular Prism
With this interactive lesson, learners compute the surface area of rectangular prisms. They visit an online investigation applet and record data on the provided handout. Pair this lesson with the volume lesson by the same publisher as an...
Curated OER
Highs and Lows
Solve problems using integration and derivatives. By using calculus, learners will analyze graphs to find the extrema and change in behavior. They then will identify the end behavior using the derivatives. Activities and handouts are...
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.
Curated OER
Fractals and the Chaos Game
Pupils explore the concept of fractals. In this fractals lesson, students play the "Chaos Game" via an applet. Pupils place dots on the screen to recognize that they have created Sierpinski's Triangle.
Beacon Learning Center
Angles and Algebra
Middle schoolers calculate angle measure for triangles and complementary/supplementary angles. After a lecture/demo, students utilize a worksheet imbedded in this plan to gain practice.
Curated OER
Determining Angle Measure with Parallel Lines
Students observe and solve examples of corresponding angle postulates, alternate interior angle theorems, and exterior and consecutive angles. They complete the Determining Angle Measure With Parallel Lines worksheet.