EngageNY
Experiments with Inscribed Angles
Right angles, acute angles, obtuse angles, central angles, inscribed angles: how many types of angles are there? Learners first investigate definitions of inscribed angles, central angles, and intercepted arcs. The majority of the lesson...
EngageNY
Multiplying and Dividing Expressions with Radicals
That's radical! Simplifying radicals may not be exciting, but it is an important skill. A math lesson provides explanations of properties used throughout the material. Scholars practice skills needed to multiply and divide radical...
EngageNY
How Far Away Is the Moon?
Does the space shuttle have an odometer? Maybe, but all that is needed to determine the distance to the moon is a little geometry! The lesson asks scholars to sketch the relationship of the Earth and moon using shadows of an eclipse....
Utah Education Network (UEN)
Geo Shapes
Invite your first graders to compose and decompose two and three-dimensional figures with this fun, hands-on instructional activity. They investigate and predict the results of putting together and taking apart two-dimensional shapes...
CK-12 Foundation
Congruent Angles and Angle Bisectors: Bisecting Pepperoni Pizza
Who doesn't like pizza? A creative lesson uses a piece of pizza to explore angle bisectors and congruent angles. Young scholars work through a simulation to create congruent slices of pizza by analyzing an angle bisector. They then...
Curated OER
Math Mouth!
Students examine and discuss math vocabulary. They participate in various games involving the math vocabulary. Use this as a supplement.
EngageNY
Equations for Lines Using Normal Segments
Describing a line using an algebraic equation is an essential skill in mathematics. The previous activity in the series challenged learners to determine if segments are perpendicular with a formula. Now they use the formula to determine...
Curated OER
Understanding Proportions and Scale Drawings
Proportions are ratios found using multiplication or division. Middle schoolers solve measurement problems, find a figure's missing dimension, and find the distance between two points. Resource features four lesson plans with detailed...
EngageNY
Special Relationships Within Right Triangles—Dividing into Two Similar Sub-Triangles
Why are right triangles so special? Pupils begin their study of right triangles by examining similar right triangles. Verifying through proofs, scholars recognize the three similar right triangles formed by drawing the altitude. Once...
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
Parallel and Perpendicular Lines
Use what you know about parallel and perpendicular lines to write equations! Learners take an equation of a line and write an equation of a line that is parallel or perpendicular using slope criteria. They then solve problems to...
EngageNY
Prove the Pythagorean Theorem Using Similarity
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.
EngageNY
Using Trigonometry to Determine Area
What do you do when you don't think you have enough information? You look for another way to do the problem! Pupils combine what they know about finding the area of a triangle and trigonometry to determine triangle area when they don't...
EngageNY
Perimeter and Area of Triangles in the Cartesian Plane
Pupils figure out how to be resourceful when tasked with finding the area of a triangle knowing nothing but its endpoints. Beginning by exploring and decomposing a triangle, learners find the perimeter and area of a triangle. They then...
EngageNY
Construct a Square and a Nine-Point Circle
Anyone can draw a square, but can you CONSTRUCT a square? Here is a resource that challenges math scholars to create steps to finish their own construction. They test their ability to read and follow directions to complete a construction...
CK-12 Foundation
Identification of Angles by Vertex and Ray
Angle ABC is not the same as angle BCA, but it is the same as angle CBA. Help your classes understand naming conventions of angles and, more importantly, the importance of naming angles correctly. Scholars practice the parts of the angle...
Curated OER
Investigating Shapes in Our World
First graders explore shapes. In this geometry lesson, 1st graders make shapes with geo-boards, use play-dough to make three-dimensional figures, and make a shape book using pre-cut shapes.
Curated OER
Geo Shapes
First graders listen as the book, "Try It With Triangles" is read to the class. They name the geometric shapes that they see in the story and view the Shape Vocabulary Cards as they name them from the book. They then cut out the...
Curated OER
Geo Jammin' - Day 3, Lesson 11: Poly Doodles All Day
Students explore geometric vocabulary through creation of shapes on a geoboard. They present design attributes, transfer of design, and color-coding components mix to create a fun and exciting instructional activity that stretches...
Curated OER
Similar and Congruent Triangles
Students create and classify different types of triangles using an online geo-board. They explore the concepts of similar and congruent as they discover how to draw similar and congruent triangles.
Curated OER
Geo-Critters (Geometry Critters)
Students read the book The Math Curse by Jon Scieszka and study geometry. In this geometry lesson, students identify geometric shapes and their properties. Students create a geo-critter.
Curated OER
Math: Congruent and Similar Figures
Eighth graders use geo-boards to create similar and congruent figures and find their corresponding sides. Using the geo-board paper, they draw the shapes they create on the geo-boards. With partners,students create similar and congruent...
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
Properties of Tangents
You know about the tangent function, but what are tangent lines to a circle? Learners investigate properties of tangents through constructions. They determine that tangents are perpendicular to the radius at the point of tangency, and...