What is the same about intersecting lines, perpendicular lines, and parallel lines

Parallel lines are lines that has same slope but different y intercept

Perpendicular line has a slopes that are opposite sign and oppose numbers and if you plot them you will find the intersection tent intercept could be the same or different
Example
Y= -1/2+8
Y=2/1+5

One unique triangle, because those angles add up to 180, and that's how many degrees there are in one triangle.

Idon't know the answer