Lines D and E are parallel to each other. A parallel line set is when 2 (or more) lines have the same slope with different intercepts. The 2 lines will never meet and will always remain consistently apart from each other.
Lines D and C are perpendicular to each other, which means that go exactly the opposite direction. If 2 lines are perpendicular, they will always meet at a right angle, regardless of the y-intercept.
1 and 3 are special angles because they will be the same, no matter how the lines would have met. The angles to the right of 1 and 3 will always be equal to 180-(measure of angle 1 or 3).
