GeoGebra
Conjectures and Proof
Transform proofs using triangle rotations. By rotating a triangle around various points, class members develop proofs. Participants prove relationships of alternative interior angles formed by parallel lines and the sum of the interior...
Radford University
Parallel Lines Cut by a Transversal
Use the parallel lines to find your way. After first reviewing geometric constructions and the relationships between angles formed by parallel lines and a transversal, young mathematicians write proofs for theorems relating to parallel...
Ohio Department of Education
I Can Name that Angle in One Measure! - Grade Eight
Collaborative groups work with geometry manipulatives to investigate conjectures about angles. They create a graphic organizer to use in summarizing relationships among angles in intersecting, perpendicular and parallel lines cut by a...
Curated OER
Linear Equations and Angles
In this geometry activity, students identify the length of the different sides using equations. They solve for the unknown to identify similarity and congruence in angles and sides. There are 22 questions.
Curated OER
Exploring Angle/Pair Relationships
Students find missing angles and sides of triangles. In this geometry lesson, students create intersecting lines to measure angles. They use Cabri Software to create virtual angles.
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
Inscribed Angles
Students calculate the inscribed angle of a triangle. In this geometry instructional activity, students identify the angle created by intersection of a triangle and a circle. They see the relationship between the arc and the angle.
Curated OER
Investigating AAS
Young scholars investigate the theorems of ASA, AAS, AAA and ASA. In this geometry lesson, students discuss the theorems of triangles and how it is used to solve for missing sides or angles. They review how two angles are formed by two...
Curated OER
Trigonometric Functions of Acute Right Triangles
Students derive the six trigonometric functions. In this trigonometry instructional activity, students show their understanding of trigonometric functions as they relate the right triangles. They find the missing angles and side use trig...
Curated OER
Circles and Angles
Students identify tangents, chords and secants. In this geometry lesson, students graph circles and identify angles created by secant lines, tangent lines and chords.
Curated OER
Angles, Lines and Transversals
Students identify and determine angle pair relationships. In this geometry lesson, students identify different angles of parallel lines that are cut by transversals. They identify interior and exterior angles after watching a video.
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...
Beacon Learning Center
Angles and Algebra
Students calculate angle measure for triangles and complementary/supplementary angles. After a lecture/demo, students utilize a worksheet imbedded in this plan to gain practice.
Curated OER
Determining Angle Measure with Parallel Lines
High schoolers observe and solve examples of corresponding angle postulates, alternate interior angle theorems, and exterior and consecutive angles. They complete the Determining Angle Measure With Parallel Lines worksheet.
Curated OER
Rays and Angles
Students view examples of a ray, opposite rays, collinear rays, angles, and straight angles. They discuss and demonstrate how to use a protractor and complete worksheet problems on rays and angles.
Curated OER
Measuring Angles
In this measuring angles learning exercise, 10th graders solve and complete 8 various types of problems. First, they use a protractor to find the measure of each angle shown. Then, students find the missing angle measures. They also...
Curated OER
How Do You Pay a Complement to an Angle?
Students observe and solve examples of the complementary angle theorem. They complete the How Do You Pay a Complement to an Angle worksheet, and write a response in their math journal.
Curated OER
Math Vocabulary Definitions-Multiple Choice
In this math vocabulary worksheet, students complete 15 multiple choice problems, choosing the correct definition for a set of math terms. A reference web site is included for additional activities.
Curated OER
Math Vocabulary Blackout worksheet
In this math vocabulary worksheet, students read the definition of the math vocabulary word and then write the word. Students write 15 math vocabulary words.
Curated OER
Math Vocabulary Spelling Worksheet
In this math vocabulary instructional activity, students read the math vocabulary definitions and write in the missing letters to the vocabulary words. Students complete 15 words.
Curated OER
Math Vocabulary Letter Shapes
In this math vocabulary worksheet, students match the math vocabulary definitions to the letter shapes. Students write in 8 words in the letter shapes.
Curated OER
Math Vocabulary Multiple Choice Words Worksheet
In this math vocabulary worksheet, students complete multiple choice problems where they match the correct math vocabulary word to its definition. Students complete 15 questions.
Curated OER
Perimeter
Students study about perimeter and the units used to measure perimeter using a variety of materials including their hands, feet, rulers, and computer applets. They understand such attributes as length, area, weight, volume, and size of...
Curated OER
Geometry: Lesson 8
Eighth graders engage in a lesson that is concerned with the finding of angles that are found in different two dimensional figures. They compare and contrast exterior and interior angles while also determining the unknown measures of...