The triangles are similar (given), so the measures of the angles in degrees are the same, that is, A=D, B=E, C=F.
So C=F=65, D=A=30. B=E=180-(30+65)=180-95=85.
The side ratios of the two triangles are constant. BC/AB=EF/DE, BC/20=28/35=4/5. BC=(4/5)20=16.