Lesson Plan
Curated OER

Inscribed Angles

For Teachers 9th - 10th
Students calculate the inscribed angle of a triangle. For this geometry lesson, students identify the angle created by intersection of a triangle and a circle. They see the relationship between the arc and the angle.
Lesson Plan
Curated OER

Exploring Geometric Mean

For Teachers 8th - 10th
Students solve problems using geometric means. In this geometry lesson, students create altitudes in right triangles. They use Cabri software to move the triangle around and observe different sides and angles.
Lesson Plan
Curated OER

Exploring Geometric Mean

For Teachers 8th - 10th
Student identify the solution using geometric mean. In this geometry lesson, students create right triangles where the altitude of the triangle is the side containing the right angle. They modify shapes using Cabri software and observe...
Lesson Plan
Curated OER

Linear and Locomotor Movements

For Teachers 4th - 5th
Young scholars develop locomotor movements. In this dance movement lesson, students identify lines and develop creativity while performing to "Cha Cha Slide". Young scholars discuss how to create dances and difficulty of movements. 
Lesson Plan
Curated OER

Side Splitter Triangles

For Teachers 8th - 11th
Students investigate the side splitter theorem. In this geometry lesson, students estimate and solve problems dealing with ratios and proportions. They identify angles created by lines that are parallel.
Worksheet
Curated OER

Geometric Proof and Angles

For Students 10th
In this geometry instructional activity, 10th graders write two-column and paragraph proofs to prove angle pair relationships.  The one page instructional activity contains five problems.  Answers are not included. 
Lesson Plan
Curated OER

Exploring the Properties of Rectangular Prisms.

For Teachers 9th - 10th
Learners define properties of rectangular prisms. In this geometry lesson, students identify the relationship between two and three dimensional objects. They use Cabri technology to graph their figures.
Lesson Plan
Curated OER

Exploring Properties of Rectangular Prisms

For Teachers 8th - 10th
Students explore the properties of rectangular prisms. For this geometry lesson, students identify properties of two and three dimensional shapes. They use Cabri technology to create polygons and solve problems.
Activity
Illustrative Mathematics

Slopes and Circles

For Teachers 9th - 12th Standards
An upper-level treatment of what is often presented as a basic concept (the right angle of an inscribed circle on the diameter), this activity really elevates the mathematical thought of the learner! Expected to develop formulas...
Unit Plan
Mathematics Vision Project

Circles: A Geometric Perspective

For Teachers 10th - 12th Standards
Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...
Lesson Plan
Curated OER

Geometry House!

For Teachers 4th
Fourth graders use computer drawing tools to create a house of geometric shapes.
Lesson Plan
Curated OER

Studying Special Segments in Triangles

For Teachers 8th - 10th
Students investigate special segments in triangles. In this geometry lesson plan, students graph, compare, estimate and predict findings based on their data. They differentiate between similarity and congruence of triangles.
Lesson Plan
Curated OER

Reflections

For Teachers 5th
Fifth graders create a reflection of a poygon using a Mira. They discover that a line connecting a vertiex of a polygon and the corresponding vertex of its reflection is perpendicular to the line of reflection. Students create a glide...
Lesson Plan
Curated OER

"Geotown" Scrapbook

For Teachers 3rd - 5th
Students create a scrapbook. In this geometry lesson, students use digital cameras to take pictures of geometrical concepts. Students use the pictures to create a "Geotown" scrapbook.
Lesson Plan
Curated OER

The Search for Pythagoras' Treasure

For Teachers 8th - 10th
Students identify and define properties of triangles. In this geometry instructional activity, students identify the missing sides and angles of right triangles. They use the rules of the Pythagorean Theorem to solve their problems.
Lesson Plan
Curated OER

Tangents to a Circle

For Teachers 9th - 10th
Young scholars construct tangent lines. In this geometry instructional activity, students identify the point of tangency, secant and tangent lines. They graph the lines on the Ti and make observations.
Worksheet
Curated OER

Coordinates Graphing

For Students 9th - 10th
In this geometry worksheet, students are given points to plot on a coordinate plane. They identify plotted coordinate pairs. There are 10 questions.
Lesson Plan
Curated OER

Plain Figures and Measuring Figures

For Teachers 10th - 12th
Students investigate basic geometric concepts. In this geometry lesson, students explore solids through measuring and modeling. This assignment models the importance of understanding concrete objects in geometry.      
Lesson Plan
Curated OER

A Lesson on the Root Spiral

For Teachers 9th - 10th
Students create lines and shapes with a compass and a straight edge. In this geometry lesson, students investigate square roots, irrational numbers and spirals. They explore nature to see the shapes representing mathematics and geometric...
Lesson Plan
Curated OER

Diagonals to Quadrilaterals II

For Teachers 8th - 10th
Pupils identify the properties of different polygons. In this geometry lesson, students find the slope of a line and calculate the distance between two lines. They differentiate between similar and congruent polygons.
Worksheet
Curated OER

Triangle Fundamentals Homework

For Students 9th - 10th
In this geometry worksheet, students identify the missing angles of non right triangles using the angle sum theorem. They solve for the unknown using algebra. There are 21 questions.
Lesson Plan
Curated OER

Diagonals of Quadrilaterals

For Teachers 9th - 10th
Students find the diagonals of the quadrilaterals. For this geometry lesson, students identify and use properties of quadrilaterals. They define different parts of a quadrilateral shape.
Lesson Plan
EngageNY

Triangle Congruency Proofs (part 1)

For Teachers 9th - 10th Standards
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...
Unit Plan
1
1
EngageNY

Congruence, Proof, and Constructions

For Teachers 8th - 10th Standards
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...