At 28°, 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 62°.
28° is 7/90 of a full circle, or 7π/45 radians. If you face north and turn 28° clockwise, you end up facing between NNE and NE (closest to north-northeast (NNE)).
28° angle facts
| Angle type | Acute angle (between 0° and 90°) |
|---|---|
| Complement (adds to 90°) | 62° |
| Supplement (adds to 180°) | 152° |
| Explement (adds to 360°) | 332° |
| Radians | 7π/45 ≈ 0.488692 |
| Gradians | 31.1111 grad |
| Fraction of a turn | 7/90 (7.78%) |
| Degrees, minutes, seconds | 28° 0′ 0″ |
| Slope (grade) | 53.17% |
| Roof pitch | 6.38/12 |
| Compass bearing | between NNE and NE (closest to north-northeast (NNE)) |
Trigonometric values of 28°
| Function | Value |
|---|---|
| sin 28° | 0.469472 |
| cos 28° | 0.882948 |
| tan 28° | 0.531709 |
28° on a protractor
How to draw a 28° 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 28° 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 28°.
Drawing it a 28° 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 5.32 inches (about 5 5/16″) up that line and make a mark.
- Join the mark to the vertex. The angle at the vertex is 28°, because tan 28° ≈ 0.5317.
Where you see 28° angles
- A board sloped at 28° rises about 63.8 inches over a 10-foot (120-inch) run.
- 28° of latitude on Earth spans roughly 1,933 miles north to south.
- The Earth turns 28° on its axis in about 1 h 52 min.
- Narrow acute angles like 28° show up in ramps, roof slopes, scissors blades, the tip of a pencil and the V of a flying flock of birds.
Related angles
28° angle FAQ
What type of angle is 28°?
A 28° angle is an acute angle, because it is between 0° and 90°.
What are the complement and supplement of 28°?
The complement of 28° is 62° (together they make 90°), and the supplement is 152° (together they make 180°).
How many radians is 28 degrees?
28° = 7π/45 radians ≈ 0.4887 rad. To convert degrees to radians, multiply by π/180: 28 × π/180 = 7π/45.
What is 28° as a slope or roof pitch?
28° is a 53.2% slope, which is a roof pitch of 6.38/12 (a rise of about 6 3/8 inches for every 12 inches of run).
