Curated OER
Pythagorean Theorem by Graphic Manipulation
There are many different ways to show a proof of the Pythagorean Theorem.  Here is a nice hands-on paper cutting activity that shows a graphic representation. You can even challenge your young Pythagoreans to come up with their own...
Curated OER
Vocabulary Challenge
In this math vocabulary worksheet, students choose which multiple choice answer best defines twenty-five mathematical terms. Students place their answers on the lines provided.
Curated OER
Geometry House!
Fourth graders use computer drawing tools to create a house of geometric shapes.
Curated OER
Rounding
For this rounding worksheet, students solve 40 problems in which whole numbers are rounded to the nearest 10. 100 or 1000. Students also round to the nearest dollar.
Curated OER
Equilateral Triangles
Students examine the attribute of equilateral triangles. In this equilateral triangle lesson, students examine a number of paper triangles to determine how they are classified. They determine how triangles are depicted in Navajo rugs.
Curated OER
Geo-Mat
Students review plane figures by playing a game that resembles "Twister." They listen to directions to locate a large example of the figure which is placed on the floor.
Curated OER
Exploring Special Segments in Triangles
Students discover that four special segments have a common intersection point. They identify the position of the intersection point in triangles. They produce conjectures about areas of the divided triangles.
Shodor Education Foundation
Shodor Interactivate: Lesson: Angles
This upper elementary and middle school lesson plan introduces the concept of acute, obtuse and right angles. Also, as the lesson proceeds vertical, adjacent, alternate interior and alternate exterior angles are explored. Plenty of...
Math Open Reference
Math Open Reference: Angles
Everything you wanted to know about angles and more, including 1) how to measure angles 2) types of angles 3) angle relationships and 4) angles around a transversal.
ClassFlow
Class Flow: Angle Measurement
[Free Registration/Login Required] This flipchart uses the protractor tool to understand the classification and naming of angles: acute, obtuse and right.
Mathigon
Mathigon: Geometry: Triangles and Trigonometry: Properties of Triangles
This lesson focuses on the properties of triangles, a closed shape that has three sides, three vertices, and and three internal angles. There are different types of triangles such as a right triangle, obtuse, and acute based on the...
Oswego City School District
Regents Exam Prep Center: Angles and Triangles
On this site a viewer can learn about the different types of triangles, and categorized by either angles or sides. Tutorials are also included for interior and exterior angles of triangles. A teacher resource page includes a lesson plan...
E-learning for Kids
E Learning for Kids: Math: Pizza (Italian) Restaurant: Angles I
In this interactive website, students practice various math skills such as identifying different types of angles, use the degree symbol, estimate and measure angles, and construct angles.
OER Commons
Oer Commons: Classifying Triangles
In this lesson, students learn to classify triangles by the size of the angles and the measures of the sides. Students will use interactives to explore equilateral, isosceles, scalene, acute, obtuse, and right triangles. Included are...
CK-12 Foundation
Ck 12: Elem Math: Classifying Right Obtuse or Acute by Angle Measure
[Free Registration/Login may be required to access all resource tools.] Students watch a video and attempt practice problems on how to classify triangles based on angle measures.
Varsity Tutors 
Varsity Tutors: Hotmath: Graphing Calculator Practice Problems: Point, Line, Planes, Angles
Practice using your graphing calculator for drawing and labeling points, lines, planes, and angles. 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...
CK-12 Foundation
Ck 12: Angle Classification
[Free Registration/Login Required] Students explore classifying angles by navigating through the interactive learning module and then answering questions that go along with the module. Students can also learn more about the concept by...
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.
PBS
Pbs Learning Media: Triangles: Targeted Math Instruction
Students will learn how to apply the properties and characteristics of all triangles to solve real-world problems and identify and use the unique characteristics of right, isosceles, equilateral, acute, obtuse, and scalene triangles.
CK-12 Foundation
Ck 12: Volume of Pyramids: Right Angles in a Game of Pool
[Free Registration/Login Required] Students explore classifying angles by navigating through the interactive learning module and then answering questions that go along with the module. Students can also learn more about the concept by...
Louisiana Department of Education
Louisiana Doe: Louisiana Believes: Eureka Math Parent Guide: Angle Measure and Plane Figures
A guide to support parents as they work with their students in angle measure and plane figures.
Math Is Fun
Math Is Fun: Angles
Definitions of different types of angles along with images and an interactive tool through which you can create acute, right, straight, obtuse, and reflex angles. View the parts of an angle, and learn the proper way to label angles.
Better Lesson
Better Lesson: Finding Angles
The three types of angles, right, acute, and obtuse, exist in our everyday surroundings. Students find these angles using classroom items.
Homeschool Math
Homeschool Math: Lines, Rays, and Angles
This fourth-grade geometry lesson teaches the definitions for a line, ray, angle, acute angle, right angle, and obtuse angle. We also study how the size of the angle is ONLY determined by how much it has "opened" as compared to the whole...
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
