What are the bond angles of propane?
According to “Structure of Free Molecules in the Gas Phase”, in CRC Handbook of Chemistry and Physics, 97th Edition (2016), William M. Haynes, ed., CRC Press/Taylor and Francis, Boca Raton, FL., the bond angles in propane are

$\angle\ce{CCC}=112^\circ$ 

and

$\angle\ce{HCH}=107^\circ$ 

Therefore, the remaining bond angles should each be about

$\angle\ce{CCH}\approx109^\circ$