Big Ideas

1. Reasoning and Proof

   Essential Question How do you prove that two lines are parallel?

2. Measurement

   Essential Question What is the sum of the measures of the angles of a triangle?

3. Coordinate Geometry

   Essential Question How do you write an equation of a line in the coordinate plane?

Chapter Preview

• 3-1 Lines and Angles
• 3-2 Properties of Parallel Lines
• 3-3 Proving Lines Parallel
• 3-4 Parallel and Perpendicular Lines
• 3-5 Parallel Lines and Triangles
• 3-6 Constructing Parallel and Perpendicular Lines
• 3-7 Equations of Lines in the Coordinate Plane
• 3-8 Slopes of Parallel and Perpendicular Lines

Table of Contents