ClassFlow
Class Flow: Angles in Geometry
[Free Registration/Login Required] This flipchart is a look at angles in geometry. Drawing, labeling, measuring, special angles: (right, straight, acute, obtuse) and congruence.
ClassFlow
Class Flow: Triangles and Angles
[Free Registration/Login Required] Classify angles by their side and angles. Find angles and measure in triangles.
ClassFlow
Class Flow: Introducing Angles
[Free Registration/Login Required] Students learn the difference between obtuse, acute and reflex angles and then use the protractor to measure various angles.
ClassFlow
Class Flow: Linear Pair and Vertical Angle Discoveries
[Free Registration/Login Required] In this Flipchart, students explore linear pairs and vertical angles. Students determine the measure of interior and exterior angles.
ClassFlow
Class Flow: Measure and Draw Angles
[Free Registration/Login Required] This lesson has many student interactive tricks. It is very exciting and gets the students actively engaged as they solve problems on the board. The lesson is an introduction to angles. It also reviews...
Better Lesson
Better Lesson: What Makes a Shape? Analyzing and Script Writing
Third graders will use the bat houses we built as examples of various quadrilaterals.
Beacon Learning Center
Beacon Learning Center: Triangles Side by Side
This comprehensive web lesson describes how to classify triangles by their angle and side measurements. It provides real-world examples and exercises for students to practice the skill.
TeachEngineering
Teach Engineering: Computer Accuracy
Accuracy of measurement in navigation depends very much on the situation. If a sailor's target is an island 200 km wide, sailing off center by 10 or 20 km is not a major problem. But, if the island were only 1 km wide, it would be missed...
Math Open Reference
Math Open Reference: Constructions
Learn about drawing shapes using only a compass and straight edge or ruler with out measuring any lengths or angles.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Proof the Inscribed Angle Theorem
Dr. Math gives a student a hint on how to prove that an inscribed angle is equal to 1/2 the central angle. You should know what the central angle and inscribed angle are to utilize this site.
Alabama Learning Exchange
Alex: Arc Lengths and Sector Areas
Students will work in cooperative groups to discover the relationships between arc length, central angle measure, and circumference. They will also discover the relationship between circle area, central angle measures, and sector area....
Texas Instruments
Texas Instruments: Smile Mathematics App
This App contains five games that reinforce skills from the number and operations, geometry, and measurement standards. These games help students build skills in ordering numbers, choosing equivalent fractions, estimating and drawing...
Mangahigh
Mangahigh: Shape: Quadrilaterals Inscribed in Circles
Determine the missing angle measures of quadrilaterals inscribed in circles.
Khan Academy
Khan Academy: Constructing Triangles
Practice constructing triangles. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Oswego City School District
Regents Exam Prep Center: Parallel Lines
Material to supplement classroom instruction on parallel lines: a lesson on angles with parallel lines, a practice quiz, and a link to an investigation on angles with parallel and non-parallel lines.
PBS
Pbs: Black Kingdoms of the Nile
A geometry activity that examines the history and structure of ancient pyramids and engages students in constructing pyramid models. A comprehensive activity that considers students with diverse learning styles. Math concepts introduced...
Math Planet
Math Planet: Geometry: More About Triangles
Explores triangles and related vocabulary through examples and a video lesson.
Purple Math
Purplemath: Conventions
A "convention" is "just the way a thing is done!". This reference material lists some common conventions (notational assumptions) for geometry and trigonometry.
Better Lesson
Better Lesson: Differences With Shapes
Differences between shapes are determined through measurement skills.
University of Saskatchewan (Canada)
Finding Arc Length and Central Angle Exercises
This site provides two geometry problems involving circles. One problem has the reader find the arc length given the angle and radius, the other problem has the reader find the measure of the angle given the arc length and radius....
Other
Ohio Department of Education: Eighth Grade Achievement Test (Practice Test)[pdf]
Half-length practice test for the eighth grade OAT (Ohio Achievement Test). The test includes 15 multiple-choice and 4 open-response questions dealing with topics such as geometry (comparing volumes, angle measures), data analysis...
Math Is Fun
Math Is Fun: Using a Protractor
Students learn how to construct and measure angles using a protractor and ruler. The resource consists of a video demonstration and exploration activity.
Science and Mathematics Initiative for Learning Enhancement (SMILE)
Smile: Similarity
This site contains a lesson plan for high school age students. The objective is to discover the factor of proportionality in similar polygons and to relate this factor to the perimeters and areas of similar polygons.
Khan Academy
Khan Academy: Determine Similar Triangles: Aa
Given two triangles with some of their angle measures, determine whether the triangles are similar or not. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.