The geometry and the type of hybrid orbitals present about the central atom in BF3 is
Trigonal planar,
We can do this question in two different ways, lets calculate electron pairs for BF3. Here, B is our central atom, and we know that,
ep = V+L+A−C2 = 62 = 3
Therefore, the geometry will be trigonal planar.
Trigonal planar ⇒ sp2 hybridised
Or
Lets write electronic configuration for Boron.
⇒ sp2 hybridisation ⇒ Trigonal Planar