Explanation
-
Slope formula:
m = {y_2 – y_1}/{x_2 – x_1}
-
Parallel lines: same slope (m₁ = m₂)
-
Perpendicular lines: slopes are negative reciprocals (m₁ * m₂ = −1)
Example:
-
Line1 slope = 2 → Line2 parallel slope = 2
-
Line1 slope = 2 → Line2 perpendicular slope = −1/2