CK-12 Foundation
Ck 12: Geometry: Triangle Congruence Study Guide
[Free Registration/Login may be required to access all resource tools.] Provides an overview of triangle congruence, including key terms, properties of congruent triangles, triangle postulates and theorems, and special triangles.
CK-12 Foundation
Ck 12: Interactive Geometry: 13.3 Sas Triangle Congruence
See how two triangles are congruent it means that all corresponding angle pairs and all corresponding sides are congruent.
CK-12 Foundation
Ck 12: Interactive Geometry: 3.5 Applications of Congruent Triangles
Learn how two triangles are congruent if and only if their corresponding sides and corresponding angles are congruent.
CK-12 Foundation
Ck 12: Interactive Geometry: 3.4 Sss Triangle Congruence
Discover if two triangles are congruent it means that all corresponding angle pairs and all corresponding sides are congruent.
CK-12 Foundation
Ck 12: Geometry: Arcs and Angles Study Guide
This study guide on arcs and angles covers key vocabulary, arc measurement in degrees and radians, congruent arcs, bisecting arcs, and the angles on, inside, and outside a circle. Also covers formulas and theorems. It is available for...
Khan Academy
Khan Academy: Find Angles in Congruent Triangles
Given two triangles, determine whether they are congruent and use that to find missing angle measures. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
CK-12 Foundation
Ck 12: Geometry: Sas Triangle Congruence
[Free Registration/Login may be required to access all resource tools.] Prove two triangles are congruent with the Side-Angle-Side shortcut.
CK-12 Foundation
Ck 12: Geometry: Sas Triangle Congruence
[Free Registration/Login may be required to access all resource tools.] This concept introduces students to the SAS Triangle Postulate and how to prove that two triangles are congruent given only information about two pairs of sides and...
Khan Academy
Khan Academy: Determine Congruent Triangles
Use the triangle congruence criteria SSS, SAS, ASA, and AAS to determine that two triangles are congruent. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
CK-12 Foundation
Ck 12: Congruence Statements
[Free Registration/Login Required] Students explore the concept of congruence statements by navigating through the interactive learning module and then answering questions that go along with the module. Students can also learn more about...
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.
Oswego City School District
Regents Exam Prep Center: Organizing and Venn Diagrams With Congruent Triangles
As a resource for teachers, an activity of how to connect Venn Diagrams with the five methods of proving triangles congruent - SSS, SAS, ASA, AAS, HL - is explained.
CK-12 Foundation
Ck 12: Geometry: Alternate Interior Angles
[Free Registration/Login may be required to access all resource tools.] Use alternate interior angles to determine angle congruency and the presence of parallel lines.
CK-12 Foundation
Ck 12: Interactive Geometry: 6.7 Applications of Similar Triangles
Learn how similar triangles have congruent corresponding angles and proportional corresponding sides.
Sonoma State University
Sonoma State University: Parallel Lines and Similar and Congruent Triangles
This site defines eleven theorems relating to parallel lines and similar and congruent triangles. Links to the theorems and relevant term descriptions are provided.
CK-12 Foundation
Ck 12: Interactive Geometry: 6.3 Aa Triangle Similarity
If two triangles are similar, it means that all corresponding angle pairs are congruent and all corresponding sides are proportional. However, in order to be sure that two triangles are similar, you do not necessarily need to have...
CK-12 Foundation
Ck 12: Geometry: Alternate Exterior Angles
[Free Registration/Login may be required to access all resource tools.] Use alternate exterior angles to determine congruency and the presence of parallel lines.
CK-12 Foundation
Ck 12: Geometry: Triangle Classification Grade 8
[Free Registration/Login may be required to access all resource tools.] Classifying triangles by using angle measures and side lengths.
CK-12 Foundation
Ck 12: Asa and Aas Triangle Congruence
[Free Registration/Login Required] Students are given triangles and angles and are to determine which triangles are congruent. Click learn more to watch a video and challenge me to try a practice question.
Sonoma State University
Sonoma State University: Parallel Lines and Similar and Congruent Triangles
This site defines parallel lines, parallel lines cut by a transverse, and congruent triangles. It also contains links for related terms.
Oswego City School District
Regents Exam Prep Center: Theorems and Postulates for Geometry
Here is a partial list of theorems, postulates, and properties.
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: 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.
ClassFlow
Class Flow: Parallel Lines and Angle Relationships
[Free Registration/Login Required] Explore the relationships between parallel lines and the rules of angle measurements.