A 173° angle is obtuse because it is greater than 90° and less than 180°. Its supplement is 7°, so a 173° angle and a 7° angle side by side make a straight line.
173° is 173/360 of a full circle, or 173π/180 radians. If you face north and turn 173° clockwise, you end up facing between SSE and S (closest to south (S)).
173° angle facts
| Angle type | Obtuse angle (between 90° and 180°) |
|---|---|
| Supplement (adds to 180°) | 7° |
| Explement (adds to 360°) | 187° |
| Radians | 173π/180 ≈ 3.01942 |
| Gradians | 192.2222 grad |
| Fraction of a turn | 173/360 (48.06%) |
| Degrees, minutes, seconds | 173° 0′ 0″ |
| Compass bearing | between SSE and S (closest to south (S)) |
Trigonometric values of 173°
| Function | Value |
|---|---|
| sin 173° | 0.121869 |
| cos 173° | −0.992546 |
| tan 173° | −0.122785 |
173° on a protractor
How to draw a 173° 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 173° 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 173°.
Drawing it a 173° angle without a protractor (rise and run method)
- 173° = 180° − 7°. Draw a straight line, pick a vertex on it, and build a 7° angle on one side as follows; the angle on the other side of the new line is 173°.
- 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 1.23 inches (about 1 1/4″) up that line and make a mark.
- Join the mark to the vertex. The angle at the vertex is 7°, because tan 7° ≈ 0.1228.
Where you see 173° angles
- The Earth turns 173° on its axis in about 11 h 32 min.
- Obtuse angles like 173° appear in reclining chair backs, open laptop screens, fan blades, and the corners of many-sided polygons.
Related angles
173° angle FAQ
What type of angle is 173°?
A 173° angle is an obtuse angle, because it is between 90° and 180°.
What is the supplement of 173°?
The supplement of 173° is 7°, because 173° + 7° = 180°. A 173° angle has no complement, because it is already larger than 90°.
How many radians is 173 degrees?
173° = 173π/180 radians ≈ 3.0194 rad. To convert degrees to radians, multiply by π/180: 173 × π/180 = 173π/180.
How do I measure a 173° angle on my screen?
Open the online protractor with 173° preset, or type 173 into its "Type an angle" box. You can then drag the arms onto your own lines to compare.
