**Mathematica  136**


    f[{a_,b_,c_}]:={{a,(a+c)/2,(a+b)/2},{(a+b)/2,b,(b+c)/2},{(a+c)/2,(b+c)/2,c}}
    Graphics@Polygon@Nest[Join@@f/@#&,{{{0,0},{1,0},{.5,.8}}},3]

![enter image description here][1]


  [1]: https://i.sstatic.net/lfic4.jpg