EngageNY
Reflections
Facilitate creativity in your math class as individuals learn the definition of a geometric reflection and correctly construct a model, as well as its reflected image. They use a perpendicular bisector and circles to elaborate on...
EngageNY
Congruence Criteria for Triangles—ASA and SSS
How do you know if a pair of triangles are congruent? Use the lesson to help class members become comfortable identifying the congruence criteria. They begin with an exploration of ASA and SSS criteria through transformations and...
Curated OER
Math: Arcs and Chords
Students draw diagrams demonstrating how it is possible to two central angles to be congruent and their minor arcs are not congruent. In groups, they illustrate theorems with their constructed circles, create diameters of circles that...
Curated OER
Using Trigonometry
Fifth graders explore the use of trigonometry to find unknown sides and angles in right-angled triangles, taking the concepts that were developed in the previous unit and looking at different ways of practicing the new skills. Students...
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.
Curated OER
Length, Perimeter, and Area
Students explore the concepts of length, perimeter and area. Students develop an understanding of length, perimeter, and area. Students calculate the area and perimeter of random shapes and calculate the area and perimeter of a triangle...
Curated OER
Eye From the Sky
Students are introduced to the concept of aerial perspective and scale. Students will use satellite technology to view their neighborhoods and sketch the area surrounding their schools. They will take part in a neighborhood walk to view...
Curated OER
Irregular Fractals
Middle schoolers study and research irregular fractals and construct a few based on their research. Students practice pattern recognition skills and plane geometry skills calculating dimensions on the Fractured Pictures activity.
Curated OER
Properties of Fractals
Young scholars build a working definition of a regular fractal, they measure the concepts of dimensions and scale, they explore the concept of a logarithm and they attempt to solve simple exponential equations for the exponent both by...
Curated OER
Perpendicular Lines
In this perpendicular lines practice worksheet, students find and list examples of perpendicular lines at home, at school, and outside.
Curated OER
How Many Regular Polyhedrons Are There In This or Any Universe?
Students examine the idea of "regularity" as it pertains to geometry. In this geometry lesson students complete several assignments that are part of trihedral angles and regular polyhedrons.
Curated OER
Perimeter and Area of 2D Shapes
Students find the perimeter and area of circles, triangles, and rectangles. In this perimeter and area lesson plan, the teacher gives students formulas for each shape and measurement and works through examples on the board. While no...
Curated OER
The Distance to an Unapproachable Point
Learners use geometry or trigonometry to measure the distance of a far off point. They verify their measurements using a tape measure to check their work.
Curated OER
Unit Perimeters and Areas
Students use Geometers SketchPad to find the area and perimeter of several shapes. In this geometry lesson, students determine area of rectangles and progress through irregular polygons. None of the referenced worksheets are included...
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
Congruence Criteria for Triangles—SAS
Looking for a different approach to triangle congruence criteria? Employ transformations to determine congruent triangles. Learners list the transformations required to map one triangle to the next. They learn to identify congruence...
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
Construct and Apply a Sequence of Rigid Motions
Breaking the rules is one thing, proving it is another! Learners expand on their previous understanding of congruence and apply a mathematical definition to transformations. They perform and identify a sequence of transformations and use...
EngageNY
Similarity
Learn similarity through a transformations lens! Individuals examine the effects of transformations and analyze the properties of similarity, and conclude that any image that can be created through transformations is similar. The...
Curated OER
Exploring Trigonometric Ratios
Young scholars identify the ratios of trig functions. In this trigonometry lesson, students construct triangles and use it to derive the values of sine, cosine and tangent. They use Cabri software to create the visual of the identities.
Curated OER
Similarity and Congruence
Students explore the concept of similarity and congruence. In this similarity and congruence lesson, students identify and verify whether or not two figures are similar, congruent, or neither. Students use postulates and theorems such as...
Curated OER
Similarity and Congruence
Learners explore the concept of similarity and congruence. In this similarity and congruence lesson plan, students cut out strips of paper and form a triangle. Learners try to prove that their triangles are congruent using the SSS...
Shodor Education Foundation
An Introduction To Quadrilaterals
Young geometers investigate and apply properties of quadrilaterals. After a review and discussion of key terms, students use a computer applet to explore four-sided figures and classify them according to their attributes. The...
Shodor Education Foundation
Triangle Area
While the lesson focuses on right triangles, this activity offers a great way to practice the area of all triangles through an interactive webpage. The activity begins with the class taking a square paper and cutting in in half; can they...