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.
CK-12 Foundation
Ck 12: Interactive Geometry: 5.1 Copies of Line Segments and Angles
Construct a copy of a line segment in this interactive exercise.
Mocomi & Anibrain Digital Technologies
Mocomi: Lines and Angles
Provides details about the properties of straight lines, types of straight lines, line segments, rays, curved lines, and types of angles.
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...
Illustrative Mathematics
Illustrative Mathematics: 8.g Find the Missing Angle
In this task, 8th graders are presented with a drawing of two parallel lines connected through two line segments. They are given the measures of two angles and are asked to find a third. Aligns with 8.G.A.5.
Illustrative Mathematics
Illustrative Mathematics: G Gpe, F Tf Coordinates of Points on a Circle
For this task, students are shown a unit circle in a plane and an angle measured from the x-axis. They must determine the coordinates of the line segment for the angle and answer a question about the sum of the coordinates. The purpose...
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.
Math Open Reference
Math Open Reference: Congruent
Learn about congruent with this handy reference guide. Provides a detailed definition and examples that enhance further explanation. Includes links to related topics.