# Using Properties of Parallel Lines/

 When do we need to put converse at the end? When they're asking why the lines are parallel The two theorems that have no names If two lines are parallel to the same line, then they are parallel to each other If two lines are perpendicular to the same line then they are perpendicular to each other When all right anles are congruent to each other Right Angle Theorem They always have the same slope Parallel Lines Has a slope of zero Horizontal Lines Have an Undefined Slope Vertical Lines Lines goes up to the left Negative Slope Line goes up to the right Positive Slope measures how steep the line is Slope Formula for Slope? y2-y1 x2-x1 When is it an undefined slope? When the zero is the numerator In a coordinate plane, 2 non-vertical lines are perpendicular if and only if the product of their slopes is -1. (when the slopes are opposite reciprocals) Slopes of Perpendicular Postulate What lines are perpendicular? Horizontal and Vertical Lines AuthorLaurenCamp29 ID179950 Card SetUsing Properties of Parallel Lines/ Descriptionfkjsafkj Updated2012-10-25T23:00:00Z Show Answers