To calculate the slope you have to use the following formula.
[tex]m=\frac{y_1-y_2}{x_1-x_2}[/tex]
Where
(x₁, y₁) are the coordinates of one point of the line
(x₂, y₂) are the coordinates of another point of the line
The slope of a line is always the same, regardless the segment you use to calculate it.
For line segment AC
The point are:
A (3, 2)
C (0, 1)
The slope is
[tex]m=\frac{2-1}{3-0}=\frac{1}{3}[/tex]
For line segment AD
The point are
A (3, 2)
D (9, 4)
The slope is
[tex]m=\frac{4-2}{9-3}=\frac{2}{6}=\frac{1}{3}[/tex]
For both line segments the slope is m=1/3
