A 281° angle is reflex because it measures between 180° and 360°. It is the "outside" of a 79° angle: together they make a full 360° circle.
281° is 281/360 of a full circle, or 281π/180 radians. If you face north and turn 281° clockwise, you end up facing between W and WNW (closest to west (W)).
281° angle facts
| Angle type | Reflex angle (between 180° and 360°) |
|---|---|
| Explement (adds to 360°) | 79° |
| Radians | 281π/180 ≈ 4.904375 |
| Gradians | 312.2222 grad |
| Fraction of a turn | 281/360 (78.06%) |
| Degrees, minutes, seconds | 281° 0′ 0″ |
| Compass bearing | between W and WNW (closest to west (W)) |
Trigonometric values of 281°
| Function | Value |
|---|---|
| sin 281° | −0.981627 |
| cos 281° | 0.190809 |
| tan 281° | −5.144554 |
281° on a protractor
How to draw a 281° angle with a protractor
- Subtract from 360°: 360° − 281° = 79°. 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 79°.
- Join the vertex to the dot. The inside angle is 79°; the outside angle, going the long way around, is 281°. Draw the angle arc on the outside and label it 281°.
- With a 360° protractor you can skip the subtraction: put 0° on your first line and mark 281° directly.
Drawing it a 281° angle without a protractor (rise and run method)
- Draw a straight baseline and measure 1.94 inches (about 1 15/16″) 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 79°, because tan 79° ≈ 5.1446.
- That gives you 79°. The outside (reflex) angle is 281°.
Where you see 281° angles
- The Earth turns 281° on its axis in about 18 h 44 min.
- A 281° 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
281° angle FAQ
What type of angle is 281°?
A 281° angle is a reflex angle, because it is between 180° and 360°.
Does a 281° angle have a complement or supplement?
No. Complements add up to 90° and supplements to 180°, and 281° is already larger than both. What it does have is an explement (conjugate) of 79°, the angle that completes a full 360° circle.
How many radians is 281 degrees?
281° = 281π/180 radians ≈ 4.9044 rad. To convert degrees to radians, multiply by π/180: 281 × π/180 = 281π/180.
How do I measure a 281° angle on my screen?
Open the online protractor with 281° preset, or type 281 into its "Type an angle" box. You can then drag the arms onto your own lines to compare.
