Integrated Publishing
Plane Figures
This site describes lines and angles "as found in various plane (flat) geometric figures.".
The Math League
The Math League: Basic Terms: Parallel Lines
This tutorial provides an explanation and example of parallel lines.
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]
Math Planet
Math Planet: Geometry: Measure and Classify an Angle
Explains the terms and symbols used to discuss line angles, what an angle is, and the types of angles. Includes short video lesson demonstrating how to use a protractor to measure an angle. [0:57]
Oswego City School District
Regents Exam Prep Center: Intuitive Symmetry: Point, Line, Plane, Rotational
Investigate the concept of symmetry at this test prep site. See detailed definitions and picture examples, answer the questions in the interactive practice pages, and do the classroom activity where students use a digital camera to...
ClassFlow
Class Flow: Introduction to Geometry
[Free Registration/Login Required] This flipchart is a basic introduction to Geometry: points, lines and planes. The flipchart contains movable objects (with an emphasis on student participation) and Activotes.
CK-12 Foundation
Ck 12: Geometry: Slope in the Coordinate Plane
[Free Registration/Login may be required to access all resource tools.] Find the slope of a line given two points. Includes a video [5 min. 29 sec.], examples, and review problems along with an answer key.
CK-12 Foundation
Ck 12: Geometry: Segments From Secants and Tangents
[Free Registration/Login may be required to access all resource tools.] This concept teaches students to solve for missing segments created by a tangent line and a secant line intersecting outside a circle.
CK-12 Foundation
Ck 12: Geometry: Same Side Interior Angles
[Free Registration/Login may be required to access all resource tools.] Use same side interior angles to determine supplementary angles and the presence of parallel lines.
PBS
Pbs Learning Media: Finding the Intersection
In this Cyberchase video, Inez and Digit identify the location of the transformatron using their knowledge of parallel and intersecting lines.
Wikimedia
Wikipedia: Hyperbolic Geometry
This encyclopedia entry from Wikipedia offers a discussion on hyperbolic geometry. The site explains how the hyperbolic geometry plane is represented in two dimensions and how lines in the plane must be drawn. Other types of models for...
Texas Instruments
Texas Instruments: Traveling Shapes Motion Geometry
In this activity, students describe how to move a shape from one place to another in a plane. They learn about translations, rotations, and line reflections. [Requires Adobe Reader.]
CK-12 Foundation
Ck 12: Geometry: Properties of a Circle Study Guide
[Free Registration/Login may be required to access all resource tools.] This study guide reviews the terminology for circles (tangent, arcs, central angles) and the equation for a circle.
Texas Instruments
Texas Instruments: Introduction to Geometry
These LearningCheck documents review basic geometric vocabulary, including transformations. It includes questions about the relationship between points lines and planes.
Cuemath
Cuemath: Tangent
Learn about the tangent definition in geometry, tangent geometry, tangent to a circle, tangent line equation. Check-out the solved examples for better understanding and try your hand at the tangent line calculator or solving a few...
CK-12 Foundation
Ck 12: Geometry: Basic Geometric Definitions
[Free Registration/Login may be required to access all resource tools.] In this lesson students define and use geometric terms. Students examine guided notes, review guided practice, watch instructional videos and attempt practice problems.
University of Regina (Canada)
University of Regina: Math Central: Introduction to Slope for Middle Years Mathematics
This collection of five middle school math lessons covers the topic of plane geometry, specifically the concept of slope. The first lesson introduces students to plotting points on a Cartesian grid using a Geoboard. Lesson two moves them...
National Council of Teachers of Mathematics
The Math Forum: Analytic Geometry: Polar Coordinates
This site from The Math Forum provides great information on polar coordinates. You can access this information either by clicking on the coordinates link or just scrolling down, it is the first one listed on the page. Includes several...
PBS
Pbs Learning Media: Two Sightings, Different Information
Jackie and Matt are looking at the same object along two different lines, in this video segment from Cyberchase.
Math Planet
Math Planet: Geometry: Finding Distances and Midpoints
Discover how to find distances and midpoints by viewing examples and a video lesson. [1:07]
Math Planet
Math Planet: Geometry: Polygons
A definition, examples, and a video lesson all help to explain polygons. [0:43]
Other
Central Michigan University: Point Slope Form
This resource features information on the point-slope form in geometry. It provides a good definition, several examples, and information on various forms.
Free Math Help
Free Math Help: Geometry Vocabulary
The tutorial examines basic geometry vocabulary. Definitions and examples of a point, line, line segment, ray, and plane are included.