What is the formula for finding the midpoint of every side of a tetrahedron?

[Behrooz]

hi,evryone!
whats the result of connecting the middle of every sides of each common tetrahedron?
(please give proofs,actualy the proof is much more important than the answer)
1.squer:
2.rhornbus:
3.parallelogram:
.
.
.
(im sorry if there's in mistake in my writing)
thanks!

 

[ferman]

Interior tetrahedron

I think it is other interior tetrahedron.
See deawing.

 

[cristo]

You need to make an effort before someone will help you. Also, it will ensure you get help quicker if you state the exact question, as worded on your exercise sheet.

 

[HallsofIvy]

hi,evryone!
whats the result of connecting the middle of every sides of each common tetrahedron?
(please give proofs,actualy the proof is much more important than the answer)
1.squer:
2.rhornbus:
3.parallelogram:
.
.
.
(im sorry if there's in mistake in my writing)
thanks!

Even more important than the proof is YOU working on this yourself. What have YOU done?

 

[Behrooz]

I know the answer but not the proof

you r all right,friends!
but i don't know how to start i have drawn the shapes and i already know the answer i am thinking about the proof.
thanks everyone!

 

[Hurkyl]

of each common tetrahedron?

Er, did you mean quadrilateral?

 

[Behrooz]

No

Er, did you mean quadrilateral?

No , its just an example!
(i found the answer)