At 25°, this angle is acute, meaning it is narrower than the corner of a square. It is less than half of a right angle, and its complement (the angle that makes 90° with it) is 65°.
25° is 5/72 of a full circle, or 5π/36 radians. If you face north and turn 25° clockwise, you end up facing between NNE and NE (closest to north-northeast (NNE)).
25° angle facts
| Angle type | Acute angle (between 0° and 90°) |
|---|---|
| Complement (adds to 90°) | 65° |
| Supplement (adds to 180°) | 155° |
| Explement (adds to 360°) | 335° |
| Radians | 5π/36 ≈ 0.436332 |
| Gradians | 27.7778 grad |
| Fraction of a turn | 5/72 (6.94%) |
| Degrees, minutes, seconds | 25° 0′ 0″ |
| Slope (grade) | 46.63% |
| Roof pitch | 5.6/12 |
| Compass bearing | between NNE and NE (closest to north-northeast (NNE)) |
Trigonometric values of 25°
| Function | Value |
|---|---|
| sin 25° | 0.422618 |
| cos 25° | 0.906308 |
| tan 25° | 0.466308 |
25° on a protractor
How to draw a 25° 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 25° 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 25°.
Drawing it a 25° angle without a protractor (rise and run method)
- 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 4.66 inches (about 4 11/16″) up that line and make a mark.
- Join the mark to the vertex. The angle at the vertex is 25°, because tan 25° ≈ 0.4663.
Where you see 25° angles
- Bench chisels and plane irons are commonly ground with a 25° primary bevel.
- A board sloped at 25° rises about 56 inches over a 10-foot (120-inch) run.
- 25° of latitude on Earth spans roughly 1,726 miles north to south.
- The Earth turns 25° on its axis in about 1 h 40 min.
Related angles
25° angle FAQ
What type of angle is 25°?
A 25° angle is an acute angle, because it is between 0° and 90°.
What are the complement and supplement of 25°?
The complement of 25° is 65° (together they make 90°), and the supplement is 155° (together they make 180°).
How many radians is 25 degrees?
25° = 5π/36 radians ≈ 0.4363 rad. To convert degrees to radians, multiply by π/180: 25 × π/180 = 5π/36.
What is 25° as a slope or roof pitch?
25° is a 46.6% slope, which is a roof pitch of 5.6/12 (a rise of about 5 5/8 inches for every 12 inches of run).
