Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
West Frisian
tritich
←
Proto-Germanic
*þrīz tigiwiz
(inherited)
←
Old Frisian
thritich
(inherited)
→
English
thirty
(cognate)