A 287° angle is reflex because it measures between 180° and 360°. It is the "outside" of a 73° angle: together they make a full 360° circle.
287° is 287/360 of a full circle, or 287π/180 radians. If you face north and turn 287° clockwise, you end up facing between W and WNW (closest to west-northwest (WNW)).
287° angle facts
| Angle type | Reflex angle (between 180° and 360°) |
|---|---|
| Explement (adds to 360°) | 73° |
| Radians | 287π/180 ≈ 5.009095 |
| Gradians | 318.8889 grad |
| Fraction of a turn | 287/360 (79.72%) |
| Degrees, minutes, seconds | 287° 0′ 0″ |
| Compass bearing | between W and WNW (closest to west-northwest (WNW)) |
Trigonometric values of 287°
| Function | Value |
|---|---|
| sin 287° | −0.956305 |
| cos 287° | 0.292372 |
| tan 287° | −3.270853 |
287° on a protractor
How to draw a 287° angle with a protractor
- Subtract from 360°: 360° − 287° = 73°. 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 73°.
- Join the vertex to the dot. The inside angle is 73°; the outside angle, going the long way around, is 287°. Draw the angle arc on the outside and label it 287°.
- With a 360° protractor you can skip the subtraction: put 0° on your first line and mark 287° directly.
Drawing it a 287° angle without a protractor (rise and run method)
- Draw a straight baseline and measure 3.06 inches (about 3 1/16″) 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 73°, because tan 73° ≈ 3.2709.
- That gives you 73°. The outside (reflex) angle is 287°.
Where you see 287° angles
- The Earth turns 287° on its axis in about 19 h 8 min.
- A 287° 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
287° angle FAQ
What type of angle is 287°?
A 287° angle is a reflex angle, because it is between 180° and 360°.
Does a 287° angle have a complement or supplement?
No. Complements add up to 90° and supplements to 180°, and 287° is already larger than both. What it does have is an explement (conjugate) of 73°, the angle that completes a full 360° circle.
How many radians is 287 degrees?
287° = 287π/180 radians ≈ 5.0091 rad. To convert degrees to radians, multiply by π/180: 287 × π/180 = 287π/180.
How do I measure a 287° angle on my screen?
Open the online protractor with 287° preset, or type 287 into its "Type an angle" box. You can then drag the arms onto your own lines to compare.
