Trees

We will now draw trees. For that, we will write a method using double recursion following this prototype
[!java]void [/!]tree([!java]int [/!]steps[!scala]:Int[/!], [!java]double [/!]length[!scala]:Double[/!], [!java]double [/!]angle[!scala]:Double[/!], [!java]double [/!]shrink[!scala]:Double[/!])

To draw a tree of four levels, you have to draw a trunk of the given length, turn right of the given angle, draw a tree of level 3, turn left twice of the given angle, draw another tree of level 3, and come back to your initial location.

If a tree's trunk is of length 'len', the trunk of the next level tree will be of length 'len*shrink'.