Equations of parallel and perpendicular lines (K-A)

• Parallel lines from equation (K-A)
• Parallel lines from equation (example 3) (K-A)
• Perpendicular lines from equation (K-A)
• Writing equations of perpendicular lines (K-A)
• Writing equations of perpendicular lines (example 2) (K-A)
• Proof: parallel lines have the same slope (K-A)
• Proof: perpendicular lines have opposite reciprocal slopes (K-A)