CK-12 Foundation
Ck 12: Geometry: Exterior Angles in Convex Polygons
[Free Registration/Login may be required to access all resource tools.] In this lesson students find the measure of the exterior angles of a polygon. Students examine guided notes, review guided practice, watch instructional videos and...
Mathigon
Mathigon: Geometry: Circle and Pi: Degrees and Radians
Rather than dividing a circle into some number of segments (like 360 degrees), mathematicians often prefer to measure angles using the circumference of a unit circle - a circle with radius 1. This way of measuring angles is called...
Analyze Math
Analyze Math: Parallel Lines and Angles Problems
Try these three problems about finding the measures of different angles that arise from diagrams involving parallel lines and transversals. Detailed solutions are written out for these three problems of moderate difficulty.
Better Lesson
Better Lesson: What Angles Are on a Bat House?
Third graders are preparing to build bat houses. They have calculated surface area, identified nail placement, and will now collect data on angle types in this real-world activity.
Khan Academy
Khan Academy: Challenge Problems: Inscribed Angles
Solve two challenging problems that apply the inscribed angle theorem to find an arc measure or an arc length.
Mangahigh
Mangahigh: Shape: The Angles Inside a Triangle
Test your knowledge of the missing angle measure.
Mangahigh
Mangahigh: Shape: Use Trigonometry to Find Angles
Use trigonometry to determie the angle measures.
Mangahigh
Mangahigh: Shape: Use the Law of Sines for Finding Angles
Test your knowledge of using the law of sines to determine angle measures.
CK-12 Foundation
Ck 12: Interactive Geometry: 1.3 Polygons
Explore the structure and measurement of polygons.
Varsity Tutors
Varsity Tutors: Hotmath: Graphing Calculator Practice Problems Geometry
Practice using your graphing calculator for Geometry problems. If you get stumped or if you would like to check your work, then select the View Solution button, which is located directly under each problem.
Math Is Fun
Math Is Fun: Acute Angle
This very basic website gives a clear, simple explanation of what an acute angle is.
Mangahigh
Mangahigh: Shape: Opposite Angles
Explore opposite angles by chosing the appropriate angle for the missing degree of measure.
University of Georgia
University of Georgia: Arcs, Central Angles, Arc Length & Sector Area
This site provides practice problems for calculating central angles and calculating arc length.
ClassFlow
Class Flow: Parallel Lines and Angle Relationships
[Free Registration/Login Required] Explore the relationships between parallel lines and the rules of angle measurements.
Maths Challenge
Maths challenge.net: Equal Angles
A geometric proof. Prove two angles in this model are equal in measure.
Quia
Quia: Introduction to Angles
Use this website to practice angle definitions using a matching game format.
Quia
Quia: Introduction to Angles Flashcards
Use this website to practice angle definitions using a flash card format.
Quia
Quia: Introduction to Angles Concentration
Use this website to practice angle definitions using a concentration game format.
Quia
Quia: Introduction to Angles: Word Search
Use this website to practice angle definitions using a word search format.
Free Math Help
Free Math Help: Interior Angles of a Polygon
The Geometry tutorial discusses interior and exterior angles of a polygon. Sample exercises with explanations are included.
CK-12 Foundation
Ck 12: Geometry: Triangle Classification by Angles
[Free Registration/Login may be required to access all resource tools.] Classify different types of triangles by their angles.
Math Planet
Math Planet: Geometry: Measure Line Segments
Explores how to measure the length of a line segment through examples and a video lesson. [0:40]