function branch(length, level)
{
    if(level == 0) return
    fd(length)
    lt(45)
    branch(length/2, level-1)
    rt(90)
    branch(length/2, level-1)
    lt(45)
    bk(length)
}

function lbranch(length, angle, level)
{
    fd(2*length)
    node(length, angle, level)
    bk(2*length)
}
function rbranch(length, angle, level)
{
    fd(length)
    node(length, angle, level)
    bk(length)
}

function node(length, angle, level)
{
    if (level == 0) return;
    lt(angle)
    lbranch(length, angle, level -1)
    rt(2*angle)
    rbranch(length, angle, level-1)
    lt(angle)
}

clean()
//branch(100,6)

setPenColor("#008800")
setPos(30, -150)
lbranch(25, 20, 7)