Verified Answer :

the small triangle is 0.5/1.5
the bigger triangle is 1/3

slope=rise/run ie, when the line goes how many units, the line goes up how many units

easy way is
(x,y)
y=height
x=left-right
so
(3,1) and (6,2)
height change is
1 to 2 is 1 unit of change (this is y so it is height/rise)
3 to 6 is 3 unit off change (this is x so this is right-less/run) so
1/3=rise/run=slope

slope=1/3