quad
quadrant
Angleexact by definition
A quadrant is exactly a quarter of a full turn, 90 degrees, or π/2 radians. It names both the angle and the region: the four quadrants of the Cartesian plane and of the unit circle are the domains that trigonometric sign conventions are stated over.
Watch out: The quadrant is also an instrument, the pre-sextant device for measuring altitude at sea, and older texts use the word for the tool rather than the angle.
| 1 quad | 90 ° |
Solvers that use angle