EngageNY
Solve for Unknown Angles—Angles and Lines at a Point
How do you solve for an unknown angle? In this sixth installment of a 36-part series, young mathematicians use concepts learned in middle school geometry to set up and solve linear equations to find angle measures.
EngageNY
The Inscribed Angle Alternate – A Tangent Angle
You know the Inscribed Angle Theorem and you know about tangent lines; now let's consider them together! Learners first explore angle measures when one of the rays of the angle is a tangent to a circle. They then apply their newfound...
Illustrative Mathematics
The Geometry of Letters
Use the alphabet as a tool for teaching your class about geometric figures. Break apart capital letters into line segments and arcs. Classify angles as right, acute, or obtuse. Identify parallel and perpendicular lines. An excellent...
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.
Curated OER
Basic Geometry ... A Pathway to Angles
Help 9th graders identify lines, points, rays, and planes in geometry. They practice identifying, measuring, and drawing angles of different degrees. This is a fundamental lesson to help students learn the building blocks of geometry.
Curated OER
Geometry Lesson 7: Line Segments And Angles
Fourth graders examine and identify line segments and angles using dot paper to draw them. They look at vertical, horizontal, intersecting, parallel and perpendicular lines, draw right angles and angles that are greater than and less...
Curated OER
Lines and Angles with K'NEX
Here is a geometry lessonwhich invites learners to create models using their knowledge of lines, segments, rays, and angles. This lesson reinforces geometric vocabulary and concepts through practical application, it also includes...
West Contra Costa Unified School District
Parallel Lines Cut by a Transversal
Parallel lines seem so right for each other. It's too bad they'll never, ever meet. Learners use tracing paper to discover relationships among angles formed by two parallel lines cut by a transversal. They apply this information to find...
Utah Education Network (UEN)
The Angle Tangle
Fourth and fifth graders identify three types of angles, recognize that angles are measured in degrees, measure angles using protractors or angle rulers. They classify angles as a class, classify angles on pattern blocks, and complete a...
Curated OER
Angles
Fourth and fifth graders investigate angles and name them according to the criteria for obtuse, acute, and right angles. They examine a human-made yarn pattern on the floor of their classroom and identify angles, vertices, and types of...
EngageNY
Secant Angle Theorem, Exterior Case
It doesn't matter whether secant lines intersect inside or outside the circle, right? Scholars extend concepts from the previous lesson plan to investigate angles created by secant lines that intersect at a point exterior to the circle....
Virginia Department of Education
Lines and Angles
Explore angle relationships associated with transversals. Pupils construct parallel lines with a transversal and find the measures of the angles formed. They figure out how the different angles are related before constructing...
Curated OER
Points, Lines, Planes, and Space
In this points, lines, planes, and space worksheet, students solve word problems dealing with points, lines, planes, and space. Students complete 20 individual problems and 20 group problems.
Curated OER
Geometry/Math A Regents Questions: Angle Bisectors
In this angle bisector worksheet, students solve five short answer and multiple choice problems. Students construct angle bisectors using a compass.
West Contra Costa Unified School District
Arcs and Angles
Noah didn't construct this kind of arc. High school scholars first explore how angles can be formed in circles. They then learn relationships between angles and arcs by conducting an exploratory activity where they position and draw arcs...
Alabama Learning Exchange
Origami Geometry
Origami is an excellent way to combine Japanese culture, art, and geometric shapes into one engaging instructional activity! Scholars begin by listening to the story Sadako and the Thousand Paper Cranes and learn the origin of the...
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...
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
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...
Curated OER
Angle Relationships
Students investigate geometric relationship using conjecture about linear pairs and vertical angles. In this geometry lesson, students apply their theorems and previous geometry knowledge to solve for and find angles of linear pairs....
Curated OER
What Is Hyperbolic Geometry?
Ninth graders discuss the concept of hyperbolic geometry. They complete Internet geometry activities and write essays comparing and contrasting hyperbolic geometry to Euclidean geometry.
Virginia Department of Education
Angles, Arcs, and Segments in Circles
Investigate relationships between angles, arcs, and segments in circles. Pupils use geometry software to discover the relationships between angles, arcs, and segments associated with circles. Class members use similar triangles to...
Curated OER
Perpendicular Lines
In this perpendicular lines practice worksheet, students find and list examples of perpendicular lines at home, at school, and outside.
EngageNY
Solve for Unknown Angles—Angles in a Triangle
Assist your class with each angle of geometry as they use exterior angles to form linear pairs with adjacent interior angles. They cover multiple vocabulary terms and work practice problems, complete with justifications, before taking an...