Name

**Slopes of line segments.**
Graph	Formulas
	$\text{Horizontal line}\,$ $\alpha =0\,$ $\tan \alpha=0\,$ $m=0\,$
	$\text{Vertical line}\,$ $\alpha =90^\circ\,$ $\tan \alpha=\infty$ $m=\text{Undefined}\,$ $\text{A vertical line has no slope}\,$
	$\text{Upward line from left to right}\,$ $0 < \alpha <90^\circ\,$ $0<\tan \alpha<\infty$ $m>0\qquad\text{Positive slope}\,$
	$\text{Downward line from left to right}\,$ $90^\circ<\alpha<180^\circ\,$ $-\infty<\tan \alpha<0$ $m<0\qquad\text{Negative slope}\,$