Add substituents to draw the conformer below (sighting down the indicated bond), then rotate the back carbon to provide the Newman projection in the most stable conformation.
H
H
H
H$_3$C
H CH$_2$CH$_3$
Drawing
Atoms, Bonds and Rings
Charges
H
CH$_3$
CH(CH$_3$)$_2$
C(CH$_3$)$_3$
Undo
Reset
Remove
Done
Rotate