Curated OER
Geometry of Triangles Using a Protractor
Seventh graders use a protractor to measure angles and solve a problem involving distance. For this measuring angles with a protractor lesson plan, 7th graders calculate the distance of a line on a diagram by using a protractor to...
Virginia Department of Education
Angles in Polygons
Polygons — it's all about the angles. Groups work with dynamic geometry software to find the sum of the measures of the angles of various polygons. After finding the information for several polygons, the groups generate a formula that...
Alabama Learning Exchange
Radians: Just Another Way
Serve up angle measurements on paper plates. Pupils use paper plates and paper-folding techniques to create a unit circle with conversions for special angles. Using their plates, learners explore the relationship between angle...
Curated OER
Forming, Measuring and Labeling Angles
Pupils draw and measure angles. In this angle measurement lesson, the teacher demonstrates how to form and measure angles while explaining the parts of an angle, then students practice.
Curated OER
Poolroom Math
Students identify, name, and measure angles using playing pool as a motivator in this lesson. They measure, define, and label different angles. They then discuss how their knowledge about angles could be used in a game of pool.
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...
EngageNY
How Do Dilations Map Angles?
The key to understanding is making connections. Scholars explore angle dilations using properties of parallel lines. At completion, pupils prove that angles of a dilation preserve their original measure.
Mathematics Assessment Project
Applying Angle Theorems
Polygon ... an empty bird cage? After finding the angles of a polygon, young mathematicians use the provided methods to solve the problem in multiple ways.
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...
EngageNY
Solving for Unknown Angles Using Equations II
The third activity in the series of 29 asks learners to identify types of angles to verify angle relationships. They find unknown measures using vertical, adjacent, complementary, supplementary, and 360-degree angles.
EngageNY
Solving for Unknown Angles Using Equations
They say a picture is worth a thousand words—and your pupils may agree after this instructional activity! They read a geometric description and create a diagram from that description. Their diagrams help them find unknown measures based...
EngageNY
Solving for Unknown Angles Using Equations III
Challenge your classes to combine geometric and algebraic concepts with an activity that builds on concepts learned in the first three lessons of the series. The fourth part asks scholars to identify geometric angle relationships and use...
Curated OER
Finding the Sum of the Exterior and Interior Angles of a Polygon
Students find the sum of the angles of a polygon and construct a polygon given the number of sides. In this polygon lesson plan, students draw large polygons on the floor of the room. They measure the length of each side and the interior...
Curated OER
Interior/Exterior Polygon Angles and Tessellations
Students discover the sum of the interior and exterior angles of several polygons. In this Geometers sketchpad lesson, students work in groups to find the stated measurements of triangles, quadrilaterals, pentagons and hexagons. Students...
Curated OER
Angles
Learners identify obtuse and acute angles in comparsion to a right angle. They identify obtuse, acute, and right angles. Pupils use "Shape Measure" to construct obtuse, acute, and right angles. They review line segements to locate right...
Curated OER
Angle Relationships
Students investigate geometric relationship using conjecture about linear pairs and vertical angles. In this geometry instructional activity, students apply their theorems and previous geometry knowledge to solve for and find...
EngageNY
Unknown Angle Proofs—Proofs of Known Facts
Lead the class in a Greek history lesson plan 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...
Curated OER
Supplementary, Complementary, and Vertical Angles
By using circles that they cut out and label themselves, learners literally "get a grip" on the angles they identify: supplementary, complementary, and vertical. They solve missing measurements based on properties of supplementary,...
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...
Project Maths
Introduction to Angles
Approach the lesson from the right angle. A discussion-based lesson leads helps learners understand angles in terms of rotation. Individuals use manipulatives to explore the properties of angles and learn how to name them. The lesson is...
Curated OER
Measuring the Earth
High schoolers use principles of geometry to measure the circumference of the Earth. For this applied geometry lesson, students use mathematics to determine scientific information. They make measurements, calculate the central...
Illustrative Mathematics
Are These Right?
Is that a right triangle or a wrong triangle? Young mathematicians look at eleven different shapes and use a measuring tool of their choice to determine which triangles have right angles. Consider cutting out sets of the shapes to...
EngageNY
Unknown Angles
How do you solve an equation like trigonometry? Learners apply their understanding of trigonometric ratios to find unknown angles in right triangles. They learn the meaning of arcsine, arccosine, and arctangent. Problems include...
Illustrative Mathematics
Sum of Angles in a Polygon
How can learners use algebra to solve a geometry problem? Help learners create an equation that shows the relationship between the number of sides of a polygon and the sum of the interior angles. Students are asked to divide the...