Geometry Help
Geometry Help: Lines and Angles
Explains the basic concept of lines and angles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Math Open Reference
Math Open Reference: Points and Lines
A complete reference guide to points, lines, and planes. It provides definitions and interactive activities that enhance further explanation.
CK-12 Foundation
Ck 12: Interactive Geometry: 4.2 Theorems About Lines and Angles
Consider two parallel lines that are intersected by a transversal, and when it crosses the two others, many different angle pairs are formed. See the special properties of the angle pairs in this interactive.
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.
CK-12 Foundation
Ck 12: Plix: Vision and the Eye: The Line Up
[Free Registration/Login Required] Are your eyes playing tricks on you? This site contains parallel and skew lines that creates an optical illusion.
Texas Education Agency
Texas Gateway: Coordinate Geometry: Special Segments
The student will derive and use the slope and midpoint formulas to verify geometric relationship that include parallelism and perpendicularity of lines. Then, the student will determine an equation of a line parallel or perpendicular to...
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.
ClassFlow
Class Flow: Two Dimensional Shapes Identify and Match
[Free Registration/Login Required] This flipchart helps students to analyze and compare various two-dimensional shapes according to the vertices, sides and parallel lines. It features "containers" created in Version 3 (can be used with...
CK-12 Foundation
Ck 12: Geometry: Alternate Exterior Angles Intermediate
[Free Registration/Login may be required to access all resource tools.] This concept introduces students to alternate exterior angles and how to use them to determine whether or not lines are parallel.
CK-12 Foundation
Ck 12: Geometry: Same Side Interior Angles
[Free Registration/Login may be required to access all resource tools.] This concept introduces students to same side interior angles and how to use them to determine whether or not lines are parallel.
CK-12 Foundation
Ck 12: Geometry: Alternate Interior Angles Intermediate
[Free Registration/Login may be required to access all resource tools.] This concept introduces students to alternate interior angles and how to use them to determine whether or not lines are parallel.
Illustrative Mathematics
Illustrative Mathematics: G Gpe, G Co, G Srt Unit Squares and Triangles
In this task, students are shown three unit squares and two line segments connecting two pairs of vertices. They are asked to find the area of a triangle formed by intersecting lines. They can solve it using coordinate geometry or...
Math Is Fun
Math Is Fun: Using a Ruler and Drafting Triangle
Students learn how to construct parallel and perpendicular lines. The resource consists of video demonstrations.
CK-12 Foundation
Ck 12: Interactive Geometry: 5.3 Parallel and Perpendicular Line Constructions
Understand the step-by-step processes used to create accurate geometric figures.
Mr. Martini's Classroom
Mr. Martini's Classroom: Basic Geometry: Points, Lines, and Angles
Students can review basic geometric terms using these self-check, multiple choice questions. Three levels of questions are provided.
ClassFlow
Class Flow: Discovering Lines
[Free Registration/Login Required] This flipchart defines Parallel, Intersecting, and Perpendicular lines. It also provides opportunities to practice working with Parallel, Intersecting and Perpendicular Lines!
ClassFlow
Class Flow: Blast Off With Geometry
[Free Registration/Login Required] Learn about polygons, angles, parallel, intersecting and perpendicular lines as you journey into space. Included is an activote quiz.
ClassFlow
Class Flow: Segments and Polygons
[Free Registration/Login Required] This flipchart reviews segments, parallel and perpendicular lines and then introduces polygons including quadrilaterals. It has many real world examples of shapes and includes Activote assessment.
Annenberg Foundation
Annenberg Learner: Geometry: Circles: Inscribed Angles
Study inscribed angles in semicircles and quarter-circles. What conjectures can you make about the measure of an inscribed angle in semi- or quarter-circles?
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.
Oswego City School District
Regents Exam Prep Center: Parallel Through a Point
This step-by-step demonstration teaches students to construct a line parallel to another through a given point.
Khan Academy
Khan Academy: Equation Practice With Angles
In this practice activity, students calculate angles created when two parallel lines are intersected by a transversal. Students receive immediate feedback and have the opportunity to watch a video, get hints, or try questions repeatedly.
Oswego City School District
Regents Exam Prep Center: What Is a Locus?
This site defines what a locus is and offers links to five locus theorems. Walks you through the six "Steps to solving a locus problem."
Oswego City School District
Regents Exam Prep Center: The Basic Locus Theorems
A wealth of resources for teachers introducing locus theorems to students. Lessons cover simple definitions, provide examples and diagrams, and offer connections to real-life situations. Practice exercises offer students online quizzes...