Curated OER
Triangle in the Matrix
Young mathematicians represent a triangle with a matrix and use the determinant to find the area of three given triangles. Learners also verify the formula for area of a triangle.
Curated OER
Got Complements? with Cabri Jr.
Learners use the axes and measure angle tool to explore and calculate complementary angles with Cabri Jr. They also identify what happens to the calculation as they drag the endpoint into a different quadrant. Finally, they label each...
Curated OER
Sail Problem
High schoolers explore the proportional relationships involved in multiple parallel lines being cut by a transverse line. They complete a sail design problem, that involves finding the lengths of pieces of fabric along the edge of a sail...
Curated OER
Evaluating the Products of Chords of a Circle
Students investigate chords and make predictions. In this geometry lesson, students graph circles and calculate the measurement of each chord. They perform the calculations and make conjectures.
Wolfram Research
Wolfram Math World: Geometry
This site provides an understanding of the many types of geometry.
University of California
Geometry Junkyard
An interesting junkyard of geometry findings where people are free to add their own findings and sift through others' interesting additions.
Exploratorium
Exploratorium: Geometry Playground
Colorful explorations of geometry, taken from a museum exhibit. With sections on the geometry of light, the geometry of movement, and the geometry of patterns. Includes photo essays, videos, and activities.
That Quiz
That Quiz: Practice Test: Geometry
This resource allows users to test their geometry knowledge.
Cut the Knot
Cut the Knot!: Geometric Construction With the Compass Alone
This site explains the possible uses of a compass when drawing. There are numerous exercises for using a compass with links to the solutions - click on the red checkmarks for these. The site discusses mathematicians who contributed to...
Wolfram Research
Wolfram Math World: Math World: Geometric Construction
Offers an explanation of what a geometric construction is and what some of the tools are that are used for it, including the traditional straightedge and compass. The site explains how to construct various polygons inscribed within a...
Oswego City School District
Regents Exam Prep Center: Geometric Constructions
Learn all about the basic geometric constructions in this test prep lesson. You will explore line segments and points, and understand key terms like the terms parallel and perpendicular. Construction activities and interactive online...
Mathigon
Mathigon: Euclidean Geometry: Origami and Paper Folding
This lesson focuses on a different way to construct geometric figures without tools, Origami. The goal is to make objects out of one or more sheets of paper, without any additional tools like glue or scissors. You can create incredibly...
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.
CK-12 Foundation
Ck 12: Geometry Software for Constructions
[Free Registration/Login Required] Students explore the concept of using geometry software to construct geometric shapes by navigating through the interactive learning module and then answering questions that go along with the module....
National Council of Teachers of Mathematics
The Math Forum: Geoboard Activities
Math Forum provides a set of links to sites that are related to geoboard activities. There are several great links to lessons using geoboards. The links provide insight into how to use them, including how to perform various measurements...
Cuemath
Cuemath: Plane Shapes
A comprehensive guide for learning all about plane shapes with definitions, properties, types, solved examples, and practice questions.
Government of Alberta
Learn alberta.ca: Mathematics Glossary: Adjacent Angles
LearnAlberta.ca's Mathematics Glossary defines adjacent angles and gives several examples to illustrate the concept. [Requires Java.]
Dartmouth College
Dartmouth College: Mqed: Color Harmonies and Algebra Tiles
The design project examines geometric shapes, color harmonies, and composition. An instructor sheet and student handout are included.
PBS
Wnet: Thirteen: Ed Online: Virtual Polyhedra
Young scholars explore polyhedron's through technology and paper/ pencil constructions.
Texas Instruments
Texas Instruments: Investigating Segments in a Quadrilateral
In this activity, students use the tools of Cabri Jr to test their knowledge of geometry. They investigate the properties of the shape formed by connecting the midpoints of adjacent sides of a quadrilateral.
Texas Instruments
Texas Instruments: Cyclic Quadrilaterals
Students construct cyclic quadrilaterals and investigate their properties. They determine which quadrilaterals from the quadrilateral hierarchy are cyclic.
Texas Instruments
Texas Instruments: Measuring Angles in a Quadrilateral
In this activity, use an interactive, and investigative approach to determining the sum of the interior angles of a quadrilateral. They use Cabri Jr. to draw, measure, and calculate the characteristics of the angles of quadrilaterals.
Texas Instruments
Texas Instruments: Ti 92 + Cabri Geometry for the Not Necessarily Advanced User
This activity is a tutorial on using the Cabri Geometry application. Students' perform geometric constructions which range from simple triangles to complex conics.
Texas Instruments
Texas Instruments: Exploring Geometry and Algebra Using Cabri Jr. Application
To prove the Perpendicular Bisectors Theorem using the Cabri Jr. Application, graphically and algebraically.