# Unit 1: Analytical Geometry

- The slope of perpedicular lines are `negative reciprocal`.
- The slopes of parallel lines are `the same`
- The slope of a vertical line is `undefined`
- The slope of a horizontal line is `0`.
The general equation of a line in standard form is $`ax+by+c=0`$, where $`a,b,c \in \mathbb{Z}, a>0`$