CK-12 Foundation
Ck 12: Geometry: Proportionality Relationships Study Guide
[Free Registration/Login may be required to access all resource tools.] This study guide looks at proportionality theorems for triangles and parallel lines intersected by transversals.
Math Slice
Math Slice: Geometry Slice Special Test
A succinct test for assessing geometry concepts. Assessment is scored online giving immediate feedback. An excellent assessment tool.
CK-12 Foundation
Ck 12: Interactive Geometry: 10.4 Slope of Parallel and Perpendicular Lines
Understand how to find the slope of parallel and perpendicular lines.