Curated OER
Special Angles on Parallel Lines
Tenth graders investigate parallel lines and their special angles cut by a transversal. In this geometry lesson, 10th graders identify and find corresponding, alternate interior, and alternate exterior angles formed when parallel lines...
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
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...
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
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...
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
Hypatia: Angles
Introduce your young geometers to Hypatia, the first noted Greek female mathematician, and the properties of angles. Though this resource is missing worksheets that are needed to complete the lesson, the structure is sound and learning...
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.
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
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....
Curated OER
Constructing Midsegments of Triangles
Students construct midsegments. In this geometry lesson, students make conjectures and apply properties of triangles to solve problems. They complete an activity on the computer.
EngageNY
Informal Proof of AA Criterion for Similarity
What does it take to show two triangles are similar? The 11th segment in a series of 16 introduces the AA Criterion for Similarity. A discussion provides an informal proof of the theorem. Exercises and problems require scholars to apply...
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
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
Incredible Edible Bridges
Students create a bridge using engineering and geometric concepts. In this geometry lesson plan, students identify the missing measures of polygons sides and angles. They work together to solve real life situation using problem solving...
Curated OER
Strongest Polygon
Pupils define and identify shapes by name. In this geometry lesson, students construct, identify and compare polygons based on the number of sides. They classify each shape based on their angle sum theorem.
EngageNY
Similarity and the Angle Bisector Theorem
Identifying and verifying reproducible patterns in mathematics is an essential skill. Mathematicians identify the relationship of sides when an angle is bisected in a triangle. Once the pupils determine the relationship, they prove it to...
EngageNY
Congruence Criteria for Triangles—SAS
Looking for a different approach to triangle congruence criteria? Employ transformations to determine congruent triangles. Learners list the transformations required to map one triangle to the next. They learn to identify congruence if...
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,...
Curated OER
The Tipping Point
Students rewrite word problems and solve using math. In this word problem lesson, students gather data and observe the data. They relate this process to the scientific method and math. They review their data to be able to answer...
Curated OER
Polygons All Around Us!
Students explore the concept of polygon properties. In this polygon properties lesson, students draw polygons with different numbers of sides such as pentagons, octagons, hexagons, etc. Students identify different geometric shapes in the...
Curated OER
Angle Action
Students measure and label specified angles. In this angles lesson, students use a protractor to find angles that are acute, obtuse, and reflexive. Students then label each angle and match the angles the correct definition. This lesson...