"inclined to think" might have been better wording, but from Merriam-Webster:
inclined adjective
in·clined in-ˈklīnd, sense 2 also ˈin-ˌklīnd
1: having inclination, disposition, or tendency
2a: having a leaning or slope
2b: making an angle with a line or plane
The intended meaning (1) is apparently more common than the literal one you're making it out to be (2a).