on pic you see that blue color has the same area as red one (and they are not sliced)

i need to find new base and new h that it will have half of original tri area [to be more precise for triangle i need the point ].And for tetrahedron thing i think i will have to start from that tip of pyramid, otherwise it will break my calculations :x

for thetrahedron it seems it has the same base * height problem, anyway i need to find the point that lies on new base if i find new h for that base, so it will have half volume of original one, i will be able to easily claculate the point for it

all triangle vertices are known, (for thetrahedron base and h is known too). triangle can be any triangle.