Question

Line segments, AB, BC, CD, DA create the quadrilateral graphed on the coordinate grid above. The equations for two of the four line segments are given below. Use the equations of the line segments to answer the questions that follow.

Answer 1

1. AB is paralell to CD because they have the same slope (1/3)

2. AB is perpendicular to CD because the slope of AB is 1/3 and the slope of CD is -3

A line with a slope m is perpendicular to a line with a slope -1/m

3. AB is perpendicular to AD, because the slope of AB is 1/3 and the slope of AD is -3

A line with a slope m is perpendicular to a line with a slope -1/m

DC is perpendicular to BC, because the slope of DC is 1/3 and the slope of BC is -3

A line with a slope m is perpendicular to a line with a slope -1/m