what is the slope

Let the vertex of the angle lie at  (0,0)

Note that  we move 6  units to the right and 4  units up to get to the point  ( 6 ,4)  that is the top right vertex of the triangle

So...we have the points  (0,0)  and ( 6,4)

And  slope  =  [  subtract the y  coordinates of each point in some order ]

                       __________________________________________________

                        [ subtract the   x coordinates of each point in the same order ]

So we have

[  4 - 0 ]               4               2          rise

_______   =       ___   =      __   =   ____

[ 6 - 0  ]                6              3          run