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EngageNY
Dividing the King’s Foot into 12 Equal Pieces
Apply, apply, apply! A measurement lesson applies a number of concepts to help learn a new construction. Scholars learn to divide a segment into n equal parts using a method that uses the Side Splitter Theorem and a method that...
Curated OER
Geometry - Angles Overview
Learners address 14 questions that include naming all pairs of opposite and supplementary angles for sets of intersecting lines and then, finding the measure of the unknown angle. They determine the measure of the angle that is...
EngageNY
Incredibly Useful Ratios
Start the exploration of trigonometry off right! Pupils build on their understanding of similarity in this lesson that introduces the three trigonometric ratios. They first learn to identify opposite and adjacent...
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
Unknown Angles
How do you solve an equation like trigonometry? Learners apply their understanding of trigonometric ratios to find unknown angles in right triangles. They learn the meaning of arcsine, arccosine, and arctangent. Problems include...
Illustrative Mathematics
Finding an Unknown Angle
Teach your class how to apply their knowledge of geometry as they explore the unknown. In order to find an unknown angle, students must understand that rectangles have four interior right angles, that right angles have 90 degrees, and...
Virginia Department of Education
Lines and Angles
Explore angle relationships associated with transversals. Pupils construct parallel lines with a transversal and find the measures of the angles formed. They figure out how the different angles are related before constructing...
EngageNY
Unknown Angle Proofs—Proofs of Known Facts
Lead the class in a Greek history lesson 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...
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....
Discovery Education
Discovering Math: Exploring Geometry
Apply geometric properties and formulae for surface area and volume by constructing a three-dimensional model of a city. Learners use similar and congruent figures and transformations to create a city of at least 10 buildings. They trade...
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
Rotations
Searching for a detailed lesson to assist in describing rotations while keeping the class attentive? Individuals manipulate rotations in this application-based lesson depending on each parameter. They construct models depending on the...
Curated OER
Shapes and Angles
Are your geometry whizzes learning about angles and shapes? This online worksheet gives 10 multiple choice questions based on images and word problems. Concepts include deducting angle degree, classifying shapes, and identifying angle...
Curated OER
Vocabulary and Concept Development: EDI
The roots metro/meter and therm are the focus of a vocabulary building presentation that includes concise definitions, color-coded examples, and opportunities for guided and independent practice. Part of a series of roots and affixes...
Shodor Education Foundation
Sets and the Venn Diagram (Beginner)
Venn diagrams are helpful in understanding the idea of a set and using attributes to sort items. This basic plan is an introduction with an added bonus of an applet that can be used to demonstrate the activity. If a classroom of...
Curated OER
What's the Area?
Practice finding the area of squares and rectangles. Complete with a grid for third graders to measure each side, this resource will be helpful. Though the shapes vary in size, they all have four sides to make measurement easy. Pupils...
National Security Agency
Classifying Triangles
Building on young mathematicians' prior knowledge of three-sided shapes, this lesson series explores the defining characteristics of different types of triangles. Starting with a shared reading of the children's book The Greedy...
Inside Mathematics
Hopewell Geometry
The Hopewell people of the central Ohio Valley used right triangles in the construction of earthworks. Pupils use the Pythagorean Theorem to determine missing dimensions of right triangles used by the Hopewell people. The assessment task...
EngageNY
Solve for Unknown Angles—Transversals
Lead your class on an exciting journey through the world of math as they review geometry facts and solve for unknown angles. They learn how to use auxiliary lines and congruent angles to correctly complete each practice problem...
EngageNY
Scale Drawings
Are you searching for a purpose for geometric constructions? Use an engaging approach to explore dilations. Scholars create dilations using a construction method of their choice. As they build their constructed dilation, they...
Mathematics Assessment Project
Temple Geometry
Temper your excitement of temple geometry. Using algebraic and geometry concepts to determine various measurements in a circle diagram, scholars determine the shaded area of the diagram.
Curated OER
Does Your Field Measure Up
Students measure angles using a plane table kit. In this geometry lesson plan, students use trigonometric identities to find the values of the length of a football field.
EngageNY
Scale Factors
Is it bigger, or is it smaller—or maybe it's the same size? Individuals learn to describe enlargements and reductions and quantify the result. Lesson five in the series connects the creation of a dilated image to the result. Pupils...
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...