# Geometry: 3.3 Proving Lines Parallel

- Author:
- Alex Dostal

- Topic:
- Geometry, Straight Lines

Drag A and C to manipulate the lines. What conjectures can you make about the relationships between the given angles and the slopes of the given lines?
*Hint: What is the relationship of the green angles? The red angles? Can you determine other unmarked angle measures in the diagram?