EngageNY
Angle Sum of a Triangle
Prove the Angle Sum Theorem of a triangle using parallel line and transversal angle relationships. Pupils create a triangle from parallel lines and transversals. They find angle measures to show that the angles of a triangle must total...
Curated OER
Corresponding Angles Worksheet
In this geometry learning exercise, 10th graders find missing angles using parallel lines angle theorem with a transversal. There are 6 problems with an answer key to all 6 problems.
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...
Curated OER
Tile Patterns I: Octagons and Squares
This can be used as a critical thinking exercise in congruence or as a teaching tool when first introducing the concept. Four octagons are arranged in such a way that a square is formed in the middle. With this information, geometry...
Curated OER
Exploring Characteristics Needed to Prove Two Trianlges Congruent
Tenth graders explore congruent triangles. In this geometry lesson, 10th graders investigate the conditions necessary to prove two triangles congruent. The lesson combines dry erase board activities and the use of technology.
Virginia Department of Education
High School Mathematics Geometry Vocabulary Word Wall Cards
Having a good working knowledge of math vocabulary is especially important for geometry learners. Here are 119 pages worth of wonderfully constructed definitions, constructions, formulas, properties, theorems, and postulates. This is a...
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...
Curated OER
Fun Wth Angles
Fourth graders explore angles in everyday life. In this angles lesson, 4th graders view examples of angles, then search magazines, newspapers and catalogues for more examples. Students work in pairs and check each other's work.
Curated OER
Diagnostic Test: Angles & Parallel Lines
In this diagnostic test worksheet, students solve problems involving angles, parallel lines, and perpendicular lines. They identify alternate interior angles, alternate exterior angles, and corresponding angles. Students find the...
Curated OER
Review of Geometry I
In this review worksheet, students identify the characteristics of intersecting and parallel lines They explore vertical, supplementary, alternate interior, alternate exterior and corresponding angles. This two-page worksheet contains...
Curated OER
Transformations in the Coordinate Plane
Your learners connect the new concepts of transformations in the coordinate plane to their previous knowledge using the solid vocabulary development in this unit. Like a foreign language, mathematics has its own set of vocabulary terms...
Curated OER
Corresponding Sides and Angles of Similar Triangles
Students differentiate between corresponding sides ad angles of two triangles. In this geometry lesson, students identify the differences as well as the similarities between two triangles. They differentiate between similar and...
Mathematics Vision Project
Circles: A Geometric Perspective
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...
Willow Tree
Ratios and Proportions with Congruent and Similar Polygons
Investigate how similar and congruent figures compare. Learners understand congruent figures have congruent sides and angles, but similar figures only have congruent angles — their sides are proportional. After learning the...
Curated OER
Angles and Similarity
Students identify triangles as similar or congruent. In this geometry lesson plan, students drag triangles around on the navigator to see the effect of different angles on the shape of the triangle. They discuss angle similarity and...
Curated OER
Measurement of a Central Angle
Students calculate the measurement of a central angle. In this geometry lesson, students identify properties of circles. They use Cabri software to create and analyze graphs.
Curated OER
Transversal and Angles
Tenth graders identify angles formed by parallel lines and a transversal. Using meter sticks and bolts, they perform hands-on activities to demonstrate the properties of parallel lines and congruent angles. They color code diagrams to...
Curated OER
Parallel Lines
Based on two sets of parallel lines intersected by a transversal, your young geometers determine the measures of 10 angles by applying the definitions of vertical, corresponding, alternate interior, and alternate exterior angles. When...
Virginia Department of Education
Similar Figures
How similar do figures have to be to be similar figures? Individuals learn to identify similar figures by verifying that angles are congruent and sides are proportional. Additionally, they match the corresponding parts of similar figures.
EngageNY
Mid-Module Assessment Task - Geometry (Module 1)
How do you prepare class members for the analytical thinking they will need in the real world? An assessment requires the higher order thinking they need to be successful. The module focuses on the concept of rigid transformations...
Virginia Department of Education
How Many Triangles?
Something for young mathematicians to remember: the sum of any two sides must be greater than the third. Class members investigates the Triangle Inequality Theorem to find the relationship between the sides of a triangle. At the same...
Illustrative Mathematics
Regular Tessellations of the Plane
Bringing together the young artists and the young organizers in your class, this lesson takes that popular topic of tessellations and gives it algebraic roots. After covering a few basic properties and definitions, learners attack the...
Curated OER
Transformations
Middle schoolers solve and identify 10 different problems that include transformations and identifying translations. They determine if each figure is an example of a translation and explain how each figure may or may not be a...
Curated OER
Geometry Angles
In this geometry angles activity, 10th graders find and solve 22 problems related to determining the measure of various angles. First, they determine the measure of each angle in the first figure if lines p and q are parallel. Then,...