Parallel and Perpendicular Lines

Parallel lines are lines in a plane that never meet or intersect, no matter how far they are extended. They have the same slope.

Perpendicular lines are lines that intersect at a right angle (90 degrees). The slopes of perpendicular lines are negative reciprocals of each other.

Parallel lines can be identified in a figure by looking for lines that are equidistant from each other and do not intersect.

Perpendicular lines can be identified in a figure by looking for lines that intersect at a right angle (90 degrees).

The slope of a line is a measure of its steepness, usually represented as 'm' in the slope-intercept form of a linear equation (y = mx + b).

The slopes of parallel lines are equal.

The slopes of perpendicular lines are negative reciprocals of each other. If one line has a slope of m, the other will have a slope of -1/m.

The slope of a line parallel to a line with a slope of 2 is also 2.

The slope of a line perpendicular to a line with a slope of 5 is -1/5.

The slopes of two lines that are parallel are equal.