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: 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.
The Math League
The Math League: Corresponding Angles
This tutorial provides a definition of corresponding angles and additional information is provided on angles.
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.
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.
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.