An angle I had to cover? (3)
I believe the answer is:
lid
'cover?' is the definition.
(lid is a kind of cover)
'an angle i had' is the wordplay.
'an angle' becomes 'l'.
'i had' becomes 'id' (I'd).
'l'+'id'='LID'
'to' is the link.
(Other definitions for lid that I've seen before include "Cover from gliders" , "Removable top" , "Bottle or jar top" , "Top crust of pie" , "Top or cover" .)