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
Unknown Angle Proofs—Proofs of Known Facts
Lead the class in a Greek history activity 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 practice...
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
Angle Relationships
Tenth graders explore the angle relationships that exist when two lines intersect. In this geometry activity, 10th graders estimate the measure of given angles and use their graphing calculator tools. Students use this knowledge to find...
Curated OER
Angles and Parallel Lines
Sixth graders draw parallel and intersecting lines to observe and examine the characteristics of alternate interior angles, vertical angles, corresponding angles, and supplementary angles. Through observation, they discover the...
Curated OER
Measurement of Angles
Students measure angles that are formed by parallel lines and a transversal lines. In this angles lesson plan, students measure and define angles that are made by parallel and transversal lines. They will color code the angles based on...
Curated OER
Sail Problem
High schoolers explore the proportional relationships involved in multiple parallel lines being cut by a transverse line. They complete a sail design problem, that involves finding the lengths of pieces of fabric along the edge of a sail...
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
Perpendicular Lines
Young scholars differentiate between parallel and perpendicular lines. In this geometry lesson, students identify the different angles created by perpendicular lines and parallel lines. They name the angles that are form when parallel...
Curated OER
Parallel-o-Home
Learners investigate the usage of parallel and perpendicular shapes in the real world. For this geometry lesson, students investigate shapes for properties that are related to the real world. They relate all the properties of shape tot...
Curated OER
Triangle's Interior Angles
Given a pair of parallel lines and a triangle in between, geometers prove that the sum of the interior angles is 180 degrees. This quick quest can be used as a pop quiz or exit ticket for your geometry class.
EngageNY
Fundamental Theorem of Similarity (FTS)
How do dilated line segments relate? Lead the class in an activity to determine the relationship between line segments and their dilated images. In the fourth section in a unit of 16, pupils discover the dilated line segments are...
Curated OER
Angle Pairs
Eighth graders are introduced to the vocabulary associated with angles. They experiment with vertical angles, alternate interior angles, alternate exterior angles, and corresponding angles. They determine angle pair relationships when...
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
Alternate Interior Angles
Label angles of parallel lines to analyze the angles created by a transversal and two parallel lines. They graph their lines and observe the similarity and difference in the angles.
Curated OER
Constructing Perpendicular Bisectors
Tenth graders investigate parallel lines and the angles formed when cut by a transversal. In this geometry instructional activity, 10th graders construct perpendicular lines and discuss midpoint, segments and perpendicular bisectors....
EngageNY
Unknown Angle Proofs—Proofs with Constructions
Provide your emerging mathematicians with the tools to learn as they incorporate auxiliary lines to solve unknown angle proofs in this continuing segment. They decipher information from a diagram to uncover the missing pieces and...
Curated OER
Light Bounce
Students solve problems involving triangles. In this geometry lesson plan, students apply properties of triangles to find the missing angles and sides. They identify angles of parallel lines cut by a transversal.
Curated OER
Angle Pairs
Students identify different angle pairs. In this geometry instructional activity, students identify the different angles of two parallel lines cut by a transversal. They identify the interior and exterior angles.
Curated OER
Angle Action 1,2 and 3
Young scholars investigate angles through construction. For this geometry lesson, students use a protractor to identify the measurement of an angle. They identify angles cut by a transversal and two parallel lines.
Curated OER
Geometric Lines: Parallel / Transversal / Perpendicular
Middle schoolers in grade 7 and 8 work on outcomes related to spatial sense and geometric concepts, properties, and relationships. The lesson integrates technology and helps students be exposed to multimedia.
Curated OER
Side Splitter Triangles
Students investigate the side splitter theorem. In this geometry instructional activity, students estimate and solve problems dealing with ratios and proportions. They identify angles created by lines that are parallel.
West Contra Costa Unified School District
Investigating Similar Triangles
Let your use of the resource be in proportion to its usefulness. Pupils investigate similar triangles by measuring side lengths and considering given angle measures. The results of the investigation help develop generalizations about...
Mathematics Assessment Project
Identifying Similar Triangles
Math whizzes work with angle sums and exterior angles to figure out the measure of other angles. This particular publication provides comprehensive support in the form of an anticipatory activity, questions designed to prompt discussion,...