thanks, that the picture. the 70 degree slope was to "defeat" APDSFS round.
according article posted by p. lakowski (tank net) 60 deg. slope was sufficient enough to defeat old APC,HVAP or APDS round,but not the long rod APDSFS round,calculation show that armour plate in order "deflect" incoming APDSFS round has to be at least 70 degree.
in fact ,I did recall an artilce posted early 2006, Chinese tank enginner claim that MBT-2000 glacis armour with her 70 degree. slope offer same protection similiar to type-98 60 deg. composite glacis armour.
aside from same quality of protection the MBT-2000 chassic is much lighter