Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Belarusian
восем
←
Proto-Indo-European
*oḱtṓw
(derived)
←
Proto-Slavic
*osmь
(inherited)
→
Belarusian
восемдзесят
(compound)
→
Belarusian
васямнаццаць
(compound)