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, students must understand that rectangles have four interior right angles, that right angles have 90 degrees, and...
Curated OER
Lesson 3: Measuring Angles
Students 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
Properties of Polygons, Parallel Sides, and Right Angles
Have fun with shapes! Third graders read a set of instructions and circle the shape in the description. They work on recognizing parallel sides and right sides. Use this resource as homework after your geometry lesson.
Curated OER
Explore Right Angles
Students investigate right angles. In this geometry lesson, students define the word "angle" and create a right angle finder from an index card. Students find right angles in their classroom. As an extension activity, students try to...
EngageNY
Experiments with Inscribed Angles
Right angles, acute angles, obtuse angles, central angles, inscribed angles: how many types of angles are there? Learners first investigate definitions of inscribed angles, central angles, and intercepted arcs. The majority of the lesson...
Mathematics Vision Project
Module 4: Similarity and Right Triangle Trigonometry
Right you are to use a great resource. Starting with a lesson on dilations, scholars learn about similarity transformations and similar triangles. They use the knowledge to develop an understanding of right triangle trigonometry in later...
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...
Baylor College
Global Atmospheric Change: The Math Link
Change up the classroom atmosphere with this interdisciplinary resource. Following along with the children's book Mr. Slaptail's Curious Contraption, these math worksheets provide practice with a wide range of topics including simple...
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...
Virginia Department of Education
Classifying Angles
Don't be obtuse, this geometry unit is the just the right resource for educating the acute young minds in your class. From classifying and measuring angles, to determining the congruence of shapes, this resource covers a wide range of...
Mathematics Vision Project
Similarity and Right Triangle Trigonometry
Starting with similar triangles and dilation factors, this unit quickly and thoroughly progresses into the world of right triangle features and trigonometric relationships. Presented in easy-to-attack modules with copious application...
EngageNY
Segments That Meet at Right Angles
Can segments be considered perpendicular if they don't intersect? Learners look at nonintersecting segments on the coordinate plane and make conclusions about the lines that contain those segments. They determine if they are...
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...
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.
Illustrative Mathematics
Right Triangles Inscribed in Circles II
So many times the characteristics of triangles are presented as a vocabulary-type of activity, but in this activity they are key to unraveling a proof. A unique attack on proving that an inscribed angle that subtends a diameter must be a...
Curated OER
Three Ways to Name an Angle
Learners first name angles in three ways, then classify them as acute, obtuse or right angles. Good practice when introducing the concept of different types of angles.
AJ Reynolds
Unit 5 Section 2: Measuring Angles
An interactive assignment displays two example angles to teach how to measure them. When you click on the angles, a protractor appears! As practice, learners view a set of angles, estimate the size of each, and then enter the degrees in...
CK-12 Foundation
Identification of Angles by Vertex and Ray
Angle ABC is not the same as angle BCA, but it is the same as angle CBA. Help your classes understand naming conventions of angles and, more importantly, the importance of naming angles correctly. Scholars practice the parts of the angle...
Curated OER
Angles - Unlocking Geometry
Students investigate the concept of angles and how they are used in geometry. They construct polygons using various types of angles and then classify them according to their physical properties. Students use a computer program in order...
Curated OER
Geometric Angles
Students explore angles and their use in Geometry. Students investigate three different kinds of angles: obtuse, acute, and right angles through an online activity. They identify pairs of angles with special relationships: vertical,...
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...
K12 Reader
Kinds of Angles
Have you ever wondered how circles and angles relate to each other? Read a passage about right angles, acute angles, and obtuse angles, and answer reading comprehension questions about the information you learn.
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...
Scholastic
Study Jams! Area of a Triangle
Even though there is a wide variety of different triangles in the world, knowing a single equation allows us to find the area of each and every one of them. Follow along with this step-by-step presentation as Zoe clearly models how to...