Angle That's Not a Multiple of 90 Degrees

This page is the CodyCross answer for the clue below from Treasure Island, Group 1029, Puzzle 2 (Quartermaster).

Question is: Angle That's Not a Multiple of 90 Degrees

and the answer is: OBLIQUE

Word Meaning:

OBLIQUE — Not erect or perpendicular; not parallel to, or at right angles from, the base.

Definitions from Wiktionary.