A 273° 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 87° angle: together they make a full 360° circle.
273° is 91/120 of a full circle, or 91π/60 radians. If you face north and turn 273° clockwise, you end up facing between W and WNW (closest to west (W)).
273° angle facts
| Angle type | Reflex angle (between 180° and 360°) |
|---|---|
| Explement (adds to 360°) | 87° |
| Radians | 91π/60 ≈ 4.764749 |
| Gradians | 303.3333 grad |
| Fraction of a turn | 91/120 (75.83%) |
| Degrees, minutes, seconds | 273° 0′ 0″ |
| Compass bearing | between W and WNW (closest to west (W)) |
Trigonometric values of 273°
| Function | Value |
|---|---|
| sin 273° | −0.99863 |
| cos 273° | 0.052336 |
| tan 273° | −19.081137 |
273° on a protractor
How to draw a 273° angle with a protractor
- Subtract from 360°: 360° − 273° = 87°. 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 87°.
- Join the vertex to the dot. The inside angle is 87°; the outside angle, going the long way around, is 273°. Draw the angle arc on the outside and label it 273°.
- With a 360° protractor you can skip the subtraction: put 0° on your first line and mark 273° directly.
Drawing it a 273° angle without a protractor (rise and run method)
- Draw a straight baseline and measure 0.52 inches (about 1/2″) 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 87°, because tan 87° ≈ 19.0811.
- That gives you 87°. The outside (reflex) angle is 273°.
Where you see 273° angles
- The Earth turns 273° on its axis in about 18 h 12 min.
- A 273° 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
273° angle FAQ
What type of angle is 273°?
A 273° angle is a reflex angle, because it is between 180° and 360°.
Does a 273° angle have a complement or supplement?
No. Complements add up to 90° and supplements to 180°, and 273° is already larger than both. What it does have is an explement (conjugate) of 87°, the angle that completes a full 360° circle.
How many radians is 273 degrees?
273° = 91π/60 radians ≈ 4.7647 rad. To convert degrees to radians, multiply by π/180: 273 × π/180 = 91π/60.
How do I measure a 273° angle on my screen?
Open the online protractor with 273° preset, or type 273 into its "Type an angle" box. You can then drag the arms onto your own lines to compare.
