At 145°, this is an obtuse angle, opened up past a square corner but not yet flat. Its supplement is 35°, so a 145° angle and a 35° angle side by side make a straight line.
145° is 29/72 of a full circle, or 29π/36 radians. If you face north and turn 145° clockwise, you end up facing between SE and SSE (closest to southeast (SE)).
145° angle facts
| Angle type | Obtuse angle (between 90° and 180°) |
|---|---|
| Supplement (adds to 180°) | 35° |
| Explement (adds to 360°) | 215° |
| Radians | 29π/36 ≈ 2.530727 |
| Gradians | 161.1111 grad |
| Fraction of a turn | 29/72 (40.28%) |
| Degrees, minutes, seconds | 145° 0′ 0″ |
| Compass bearing | between SE and SSE (closest to southeast (SE)) |
Trigonometric values of 145°
| Function | Value |
|---|---|
| sin 145° | 0.573576 |
| cos 145° | −0.819152 |
| tan 145° | −0.700208 |
145° on a protractor
How to draw a 145° 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 145° 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 145°.
Drawing it a 145° angle without a protractor (rise and run method)
- 145° = 180° − 35°. Draw a straight line, pick a vertex on it, and build a 35° angle on one side as follows; the angle on the other side of the new line is 145°.
- 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 7 inches (about 7″) up that line and make a mark.
- Join the mark to the vertex. The angle at the vertex is 35°, because tan 35° ≈ 0.7002.
Where you see 145° angles
- The Earth turns 145° on its axis in about 9 h 40 min.
- Obtuse angles like 145° appear in reclining chair backs, open laptop screens, fan blades, and the corners of many-sided polygons.
Related angles
145° angle FAQ
What type of angle is 145°?
A 145° angle is an obtuse angle, because it is between 90° and 180°.
What is the supplement of 145°?
The supplement of 145° is 35°, because 145° + 35° = 180°. A 145° angle has no complement, because it is already larger than 90°.
How many radians is 145 degrees?
145° = 29π/36 radians ≈ 2.5307 rad. To convert degrees to radians, multiply by π/180: 145 × π/180 = 29π/36.
How do I measure a 145° angle on my screen?
Open the online protractor with 145° preset, or type 145 into its "Type an angle" box. You can then drag the arms onto your own lines to compare.
