Reflex angle

306 Degree Angle

17π/10 ≈ 5.340708 radians · 17/20 (85%) of a circle

Diagram of a 306 degree angle306°
Reflex angle: 306°

Key facts

306°

Angle type
Reflex angle
Explement (adds to 360°)
54°
Radians
17π/10 ≈ 5.340708
Open 306° in the online protractor

A 306° angle is a reflex angle: it is bigger than a straight line (180°) but less than a full turn (360°). It is the "outside" of a 54° angle: together they make a full 360° circle.

306° is 17/20 of a full circle, or 17π/10 radians. The minute hand of a clock sweeps 306° in 51 minutes. If you face north and turn 306° clockwise, you end up facing between WNW and NW (closest to northwest (NW)).

306° angle facts

Angle type Reflex angle (between 180° and 360°)
Explement (adds to 360°) 54°
Radians 17π/10 ≈ 5.340708
Gradians 340 grad
Fraction of a turn 17/20 (85%)
Degrees, minutes, seconds 306° 0′ 0″
Compass bearing between WNW and NW (closest to northwest (NW))

Trigonometric values of 306°

FunctionValue
sin 306° −(√5 + 1)/4 ≈ −0.809017
cos 306° √(10 − 2√5)/4 ≈ 0.587785
tan 306° −1.376382

306° on a protractor

Protractor showing 306 degrees0102030405060708090100110120130140150160170180190200210220230240250260270280290300310320330340350306°
On a 360° protractor, read 306° directly going counter-clockwise from 0°. Try it in the interactive protractor →

How to draw a 306° angle with a protractor

  1. Subtract from 360°: 360° − 306° = 54°. A standard protractor only goes to 180°, so you draw the smaller angle first.
  2. Draw a straight line with a ruler and mark the vertex at one end.
  3. Place the protractor's center mark on the vertex, line up the 0° baseline with your line, and make a dot at 54°.
  4. Join the vertex to the dot. The inside angle is 54°; the outside angle, going the long way around, is 306°. Draw the angle arc on the outside and label it 306°.
  5. With a 360° protractor you can skip the subtraction: put 0° on your first line and mark 306° directly.

Drawing it a 306° angle without a protractor (rise and run method)

  1. Draw a straight baseline and measure 7.27 inches (about 7 1/4″) along it from the vertex.
  2. At that mark, draw a line straight up at 90° and measure exactly 10 inches up it.
  3. Join the top mark to the vertex. The angle at the vertex is 54°, because tan 54° ≈ 1.3764.
  4. That gives you 54°. The outside (reflex) angle is 306°.

Where you see 306° angles

  • The Earth turns 306° on its axis in about 20 h 24 min.
  • A 306° reflex angle is what you measure when you go the "long way" around, like the outside corner of a building or a turn of more than half a circle.

306° angle FAQ

What type of angle is 306°?

A 306° angle is a reflex angle, because it is between 180° and 360°.

Does a 306° angle have a complement or supplement?

No. Complements add up to 90° and supplements to 180°, and 306° is already larger than both. What it does have is an explement (conjugate) of 54°, the angle that completes a full 360° circle.

How many radians is 306 degrees?

306° = 17π/10 radians ≈ 5.3407 rad. To convert degrees to radians, multiply by π/180: 306 × π/180 = 17π/10.

How do I measure a 306° angle on my screen?

Open the online protractor with 306° preset, or type 306 into its "Type an angle" box. You can then drag the arms onto your own lines to compare.