At 16°, 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 74°.
16° is 2/45 of a full circle, or 4π/45 radians. If you face north and turn 16° clockwise, you end up facing between N and NNE (closest to north-northeast (NNE)).
16° angle facts
| Angle type | Acute angle (between 0° and 90°) |
|---|---|
| Complement (adds to 90°) | 74° |
| Supplement (adds to 180°) | 164° |
| Explement (adds to 360°) | 344° |
| Radians | 4π/45 ≈ 0.279253 |
| Gradians | 17.7778 grad |
| Fraction of a turn | 2/45 (4.44%) |
| Degrees, minutes, seconds | 16° 0′ 0″ |
| Slope (grade) | 28.67% |
| Roof pitch | 3.44/12 |
| Compass bearing | between N and NNE (closest to north-northeast (NNE)) |
Trigonometric values of 16°
| Function | Value |
|---|---|
| sin 16° | 0.275637 |
| cos 16° | 0.961262 |
| tan 16° | 0.286745 |
16° on a protractor
How to draw a 16° 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 16° 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 16°.
Drawing it a 16° 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 2.87 inches (about 2 7/8″) up that line and make a mark.
- Join the mark to the vertex. The angle at the vertex is 16°, because tan 16° ≈ 0.2867.
Where you see 16° angles
- A board sloped at 16° rises about 34.4 inches over a 10-foot (120-inch) run.
- 16° of latitude on Earth spans roughly 1,105 miles north to south.
- The Earth turns 16° on its axis in about 1 h 4 min.
- Narrow acute angles like 16° show up in ramps, roof slopes, scissors blades, the tip of a pencil and the V of a flying flock of birds.
Related angles
16° angle FAQ
What type of angle is 16°?
A 16° angle is an acute angle, because it is between 0° and 90°.
What are the complement and supplement of 16°?
The complement of 16° is 74° (together they make 90°), and the supplement is 164° (together they make 180°).
How many radians is 16 degrees?
16° = 4π/45 radians ≈ 0.2793 rad. To convert degrees to radians, multiply by π/180: 16 × π/180 = 4π/45.
What is 16° as a slope or roof pitch?
16° is a 28.7% slope, which is a roof pitch of 3.44/12 (a rise of about 3 1/2 inches for every 12 inches of run).
