I have drawn the medians and described the lengths of the segments. I also noticed that triangles ADC and BCD share the same height, thus
Whereas the surface of triangles ACD and BCD
And so I have already made it so far as to get the halves. But I haven't got a faintest idea how to get to the sixths.
I would be most grateful if you gave your answer in simple terms. Geometry is my Achilles's heel.