Line k contains points A, B,C, and D. EA represents the difference between the y. coordinates and EC represents the difference between the x-coordinates of points A and C
Likewise, FB represents the difference between the y coordinates and FD represents the
difference between the x-coordinates of points B and D.
Use similar triangles to explain why the slope of line k is the same whether the slope is
calculated using points A and C or points B and D.