Editing Gradian (section)

==Advantages and disadvantages==

Each quadrant is assigned a range of 100&nbsp;gon, which eases recognition of the four quadrants, as well as arithmetic involving perpendicular or opposite angles.
:{|
|-
|align="right"|   0° ||align="center"| = ||align="right"|   0 gradians
|-
|align="right"|  90° ||align="center"| = ||align="right"| 100 gradians
|-
|align="right"| 180° ||align="center"| = ||align="right"| 200 gradians
|-
|align="right"| 270° ||align="center"| = ||align="right"| 300 gradians
|-
|align="right"| 360° ||align="center"| = ||align="right"| 400 gradians
|}

One advantage of this unit is that right angles to a given angle are easily determined. If one is sighting down a compass course of 117&nbsp;gon, the direction to one's left is 17&nbsp;gon, to one's right 217&nbsp;gon, and behind one 317&nbsp;gon. A disadvantage is that the common angles of 30° and 60° in geometry must be expressed in fractions (as {{sfrac|33|1|3}}&nbsp;gon and {{sfrac|66|2|3}}&nbsp;gon respectively).