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...
Illustrative Mathematics
Finding an Unknown Angle
Teach your class how to apply their knowledge of geometry as they explore the unknown. In order to find an unknown angle, learners must understand that rectangles have four interior right angles, that right angles have 90 degrees, and...
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...
Curated OER
Lesson 3: Measuring Angles
Young scholars use a protractor to measure angles. They classify angles by type: right angle, acute angles, and obtuse angles. Students build and draw right, acute, and obtuse angles. They discuss how do people in various professions use...
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
Angles - Digger and the Gang
Students explore angle estimation and measurement. In this angle lesson, students define obtuse, acute, and right angles, and practice measuring angles using a protractor. Students participate in an online angle estimation activity.
Utah Education Network (UEN)
Angles, Degrees, Protractors . . . Oh My!
Fourth and fifth graders make a protractor and identify various angle types. In this protractor and angle lesson, learners make their own protractor and use it to measure a variety of angles. They complete worksheets while identifying...
University of Exeter
Angles and Turns
Junior geometers investigate the concepts of angles and turns using straws to perform a hands on activity. This is helpful for kinesthetic learners who have a hard time with mathematics. The lesson plan includes the dialogue to be used...
Texas Instruments
Identifying a Triangle by its Sides and Angles
Identify triangles by their angle measures and side lengths by looking at and measuring angle measures and side lengths. Use Cabri Jr. to construct various triangles, then manipulate the construction to create the 6 types of triangles,...
Curated OER
An Introduction to Angles
Students identify and create angles. In this angle measurement activity, students use sticks to make models of angles, then measure and name each angle.
Curated OER
Mr. Bo Jangle, What's Your Angle?
Third graders explore angles. In this geometry lesson plan, 3rd graders identify and define acute, obtuse, and right angles. Students form angles with their bodies, find angles in picture books, and record angles found outside in their...
Curated OER
Measuring Angles
Middle schoolers explore angle measure as they estimate angle measure and measure and draw angles of less than 360 degrees. The lesson emphasizes the use of estimation when measuring angles.
EngageNY
Inscribed Angle Theorem and Its Applications
Inscribed angles are central to the lesson. Young mathematicians build upon concepts learned in the previous lesson and formalize the Inscribed Angle Theorem relating inscribed and central angles. The lesson then guides learners to prove...
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 instructional activity to investigate angles created by secant lines that intersect at a point exterior...
Curated OER
Investigation - Adrienne's Pattern Block Angles
Fifth graders investigate possible solutions to a word problem. They explore properties of polygons and right angles. Students demonstrate proper angle measurement. Students discover patterns.
Curated OER
Acute Triangles
Learners study acute triangles. They measure angles using a protractor, then classify the triangles as either right, obtuse, or acute. Everyone creates a design for a Navajo rug using only acute triangles.
Curated OER
You Can't Go Wrong with a Right Triangle 2
Upper graders use the properties of right angle trignonmetry to measure objects such as the school flagpole. They solve real world problems using these properties.
Curated OER
Sample Lesson Plan on Lines and Angles
Student complete worksheet using the definitions of lines and angle vocabulary. They define the word and follow a direction given on the worksheet such "construct a line." They complete an online tutorial on how to measure angles using a...
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...
EngageNY
More on the Angles of a Triangle
Angles and triangles: they're all connected. Uncover the connections between angles in triangles. Scholars learn how to find both exterior and interior angle measures in triangles. The lesson emphasizes the vocabulary related to these...
Curated OER
Special Right Triangles
For this special right triangle worksheet, students use the trigonometric functions to determine angle measurement or the length of one side of a right triangle. This one-page worksheet contains 18 problems. Answers are provided at the...
Curated OER
Know Your Angles
Explore types of angles and the characteristics of each. After observing a PowerPoint Presentation, learners tour the school facilities and use a digital camera to capture prescribed angles. Using the digital pictures and written...
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
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...