Parallel and Perpendicular Lines

Objective: Explain and use parallel slopes in an Algebra 1 problem.

Distinct nonvertical parallel lines have equal slopes and different intercepts; coincident lines have infinitely many shared points. No, the lines may be identical.

Objective: Explain and use perpendicular slopes in an Algebra 1 problem.

Nonvertical perpendicular lines with nonzero slopes have slopes whose product is −1; horizontal and vertical lines are also perpendicular. A vertical line.

Objective: Explain and use writing a related line in an Algebra 1 problem.

Combine the required slope relationship with a given point using point-slope form; check whether the result passes through the point. It chooses one line among many with the required slope.