DK Publishing
Using a Protractor
Learn how to measure acute, right, and obtuse angles with a protractor. After reviewing the way the protractor works, fourth graders measure nine angles on their own. For extra practice, have them measure different angles in their...
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...
Charleston School District
The Sum of Angles in a Triangle
An informative lesson contains a brief explanation of how the sum of the angles of a triangle is a line. The lesson continues with determining the missing angle in a triangle, or solving for a variable. Using the sum of the...
CK-12 Foundation
Six Trigonometric Functions and Radians: Degrees to Radians and Back Again!
How do degrees relate to radians? The interactive allows pupils to manipulate the size of an angle in a unit circle to help see that relationship. Users determine the radian measure for given degree measures of angles, realizing the...
CK-12 Foundation
Rotations in Radians: Clock Conundrum
Pupils use an interactive clock to set specific times. They apply math to an everyday task as they determine the measure of the angle formed by the hands in degrees and in radians.
Curated OER
Classification of Triangle Measurement & Perimeter
For this classification of triangles worksheet, 10th graders identify and complete 8 different problems that include determining the measurement and perimeter of various types of triangles. First, they color all right, acute, and obtuse...
Curated OER
The Angles
A very cute presentation on the four types of angles can be found in this resource. Young mathematicians are introduced to obtuse, acute, right, and reflex angles. Charming stick figures are depicted using the angles. Great for use in...
Houghton Mifflin Harcourt
Unit 6 Math Vocabulary Cards (Grade 3)
A set of 49 math vocabulary cards ranges from angle to irregular polygon to parallel lines. Each sheet contains two cards: one with the word printed in bold text and the other with the definition.
Mathematics Assessment Project
Floor Pattern
You'll never look at floor tiles the same again. An assessment task prompts learners to investigate relationships between patterns involving squares and kites to determine angle measurements. They then prove...
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
Angles and Angle Measure
In this trigonometry worksheet, students convert between degrees and radians. They use the unit circle to identify the measure of angles. There are 28 questions with an answer key.
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.
Curated OER
Angles Measure and Classify
In this angles worksheet, students solve 6 problems in which an angle is measured with a protractor. Students mark if the angle is acute, right, obtuse or straight.
Curated OER
Angles on a Line and on a Point
In this angles activity, learners solve 24 problems pertaining to angle measurements on a line and on a point. There are also calculations of adjacent angles and supplementary angles. The page is intended as an online activity but can be...
Curated OER
Using Trinonometry to Find Angle Measures
For this trigonometric ratios worksheet, students find the missing angle of 20 triangles by using sine, cosine and tangent ratios. Students compute the angle measurement of given ratios for six problems.
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.
Illustrative Mathematics
Find the Angle
This a fun problem for young geometers to play with while gaining important insight into deductive reasoning. Some will find the answers very quickly, others might take a less direct path, but all will use their knowledge of the sum of...
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...
Concord Consortium
Triangles: Angle Space
Three angles in a triangle, three-dimensional space, it all seems connected somehow. Given several different triangles, pupils use the three angles of the triangle as coordinates to plot points in three-dimensional space. They explore...
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...