A 161° angle is obtuse because it is greater than 90° and less than 180°. Its supplement is 19°, so a 161° angle and a 19° angle side by side make a straight line.
161° is 161/360 of a full circle, or 161π/180 radians. If you face north and turn 161° clockwise, you end up facing between SSE and S (closest to south-southeast (SSE)).
161° angle facts
| Angle type | Obtuse angle (between 90° and 180°) |
|---|---|
| Supplement (adds to 180°) | 19° |
| Explement (adds to 360°) | 199° |
| Radians | 161π/180 ≈ 2.80998 |
| Gradians | 178.8889 grad |
| Fraction of a turn | 161/360 (44.72%) |
| Degrees, minutes, seconds | 161° 0′ 0″ |
| Compass bearing | between SSE and S (closest to south-southeast (SSE)) |
Trigonometric values of 161°
| Function | Value |
|---|---|
| sin 161° | 0.325568 |
| cos 161° | −0.945519 |
| tan 161° | −0.344328 |
161° on a protractor
How to draw a 161° angle with a protractor
- Draw a straight line with a ruler. This is the first arm; mark the vertex at one end.
- Place the center mark of the protractor exactly on the vertex and line up the 0° baseline with your line.
- Find 161° on the row of numbers that reads 0° on your line (protractors have two rows running in opposite directions) and make a small dot at the edge.
- Remove the protractor and draw a line from the vertex through the dot. Mark the angle with an arc and label it 161°.
Drawing it a 161° angle without a protractor (rise and run method)
- 161° = 180° − 19°. Draw a straight line, pick a vertex on it, and build a 19° angle on one side as follows; the angle on the other side of the new line is 161°.
- Draw a straight baseline and measure exactly 10 inches along it from the vertex.
- At the 10-inch mark, draw a short line straight up at 90° (use a carpenter's square or the corner of a sheet of paper).
- Measure 3.44 inches (about 3 7/16″) up that line and make a mark.
- Join the mark to the vertex. The angle at the vertex is 19°, because tan 19° ≈ 0.3443.
Where you see 161° angles
- The Earth turns 161° on its axis in about 10 h 44 min.
- Obtuse angles like 161° appear in reclining chair backs, open laptop screens, fan blades, and the corners of many-sided polygons.
Related angles
161° angle FAQ
What type of angle is 161°?
A 161° angle is an obtuse angle, because it is between 90° and 180°.
What is the supplement of 161°?
The supplement of 161° is 19°, because 161° + 19° = 180°. A 161° angle has no complement, because it is already larger than 90°.
How many radians is 161 degrees?
161° = 161π/180 radians ≈ 2.81 rad. To convert degrees to radians, multiply by π/180: 161 × π/180 = 161π/180.
How do I measure a 161° angle on my screen?
Open the online protractor with 161° preset, or type 161 into its "Type an angle" box. You can then drag the arms onto your own lines to compare.
