A 279° angle is a reflex angle: it is bigger than a straight line (180°) but less than a full turn (360°). It is the "outside" of an 81° angle: together they make a full 360° circle.
279° is 31/40 of a full circle, or 31π/20 radians. If you face north and turn 279° clockwise, you end up facing between W and WNW (closest to west (W)).
279° angle facts
| Angle type | Reflex angle (between 180° and 360°) |
|---|---|
| Explement (adds to 360°) | 81° |
| Radians | 31π/20 ≈ 4.869469 |
| Gradians | 310 grad |
| Fraction of a turn | 31/40 (77.5%) |
| Degrees, minutes, seconds | 279° 0′ 0″ |
| Compass bearing | between W and WNW (closest to west (W)) |
Trigonometric values of 279°
| Function | Value |
|---|---|
| sin 279° | −0.987688 |
| cos 279° | 0.156434 |
| tan 279° | −6.313752 |
279° on a protractor
How to draw a 279° angle with a protractor
- Subtract from 360°: 360° − 279° = 81°. A standard protractor only goes to 180°, so you draw the smaller angle first.
- Draw a straight line with a ruler and mark the vertex at one end.
- Place the protractor's center mark on the vertex, line up the 0° baseline with your line, and make a dot at 81°.
- Join the vertex to the dot. The inside angle is 81°; the outside angle, going the long way around, is 279°. Draw the angle arc on the outside and label it 279°.
- With a 360° protractor you can skip the subtraction: put 0° on your first line and mark 279° directly.
Drawing it a 279° angle without a protractor (rise and run method)
- Draw a straight baseline and measure 1.58 inches (about 1 9/16″) along it from the vertex.
- At that mark, draw a line straight up at 90° and measure exactly 10 inches up it.
- Join the top mark to the vertex. The angle at the vertex is 81°, because tan 81° ≈ 6.3138.
- That gives you 81°. The outside (reflex) angle is 279°.
Where you see 279° angles
- The Earth turns 279° on its axis in about 18 h 36 min.
- A 279° reflex angle is what you measure when you go the "long way" around, like the outside corner of a building or a turn of more than half a circle.
Related angles
279° angle FAQ
What type of angle is 279°?
A 279° angle is a reflex angle, because it is between 180° and 360°.
Does a 279° angle have a complement or supplement?
No. Complements add up to 90° and supplements to 180°, and 279° is already larger than both. What it does have is an explement (conjugate) of 81°, the angle that completes a full 360° circle.
How many radians is 279 degrees?
279° = 31π/20 radians ≈ 4.8695 rad. To convert degrees to radians, multiply by π/180: 279 × π/180 = 31π/20.
How do I measure a 279° angle on my screen?
Open the online protractor with 279° preset, or type 279 into its "Type an angle" box. You can then drag the arms onto your own lines to compare.
