Explains the properties of acute, right, and obtuse angles. [5:33]

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Features a definition, examples, and a video lesson all related to angles. [0:35]

Defines and explores the law of cosines through examples and a video lesson. [1:41]

Defines and examines the law of sines through examples and a video lesson. [2:02]

Get information about trigonometric functions by viewing examples and a video lesson. [2:08]

This section explores the graphs of sine and cosine functions. It investigates how these graphs are related to coordinates for different angles in a unit circle.

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Find out how angles and symmetry come into play in the game of pool in this video adapted from Annenberg Learner’s Learning Math: Measurement.

In this activity, students will investigate properties of angles and arcs formed when chords, secants, and tangents intersect and intercept arcs in a circle. They discover several important theorems concerning circles and arc sizes. They make use of the Central Angle theorem, which ensures that the measure of a central angle of a circle is equal to the measure of its intercepted arc.

Looks at parallel lines and intersecting lines (transversals), and the angles they form. [7:08]

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

Video tutorial discusses the relationships among angles formed when a transversal intersects parallel lines. [5:54]

Video tutorial uses problems to reinforce understanding that the angles in a triangle always add up to 180 degrees. (Part 1) [3:55]

Video tutorial uses examples to provide an introduction to angles including right, acute, and obtuse angles. [8:22]

In this lesson, students calculate the perimeter of various geometric shapes and represent the perimeter with a movement phrase. They will identify the types of angles within each shape. Other students will identify the shape that was demonstrated.

In this activity, students will identify shapes found around the room by recognizing their attributes such as number of angles, vertexes, and faces.

See this lesson to help students to learn about angles and identify the number of angles in 2D shapes. Lesson plans includes introductory activity, guided practice, and independent practice.

Students will use the bat houses we built as examples of various quadrilaterals.

This book is a "flexed" version of CK-12's Basic Geometry that aligns with College Access Geometry and contains embedded literacy supports. It covers the essentials of geometry for the high school student.

CK-12 Foundation's Geometry FlexBook is a clear presentation of the essentials of geometry for the high school student. Topics include: Proof, Congruent Triangles, Quadrilaterals, Similarity, Perimeter & Area, Volume, and Transformations.