230 Degree Angle

A 230° angle is reflex because it measures between 180° and 360°. It is the "outside" of a 130° angle: together they make a full 360° circle.

230° is 23/36 of a full circle, or 23π/18 radians. If you face north and turn 230° clockwise, you end up facing between SW and WSW (closest to southwest (SW)).

230° angle facts

Trigonometric values of 230°

230° on a protractor

How to draw a 230° angle with a protractor

1. Subtract from 360°: 360° − 230° = 130°. 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 130°.
4. Join the vertex to the dot. The inside angle is 130°; the outside angle, going the long way around, is 230°. Draw the angle arc on the outside and label it 230°.
5. With a 360° protractor you can skip the subtraction: put 0° on your first line and mark 230° directly.

Drawing it a 230° angle without a protractor (rise and run method)

1. 230° = 180° − 50°. Draw a straight line, pick a vertex on it, and build a 50° angle on one side as follows; the angle on the other side of the new line is 130°.
2. Draw a straight baseline and measure 8.39 inches (about 8 3/8″) along it from the vertex.
3. At that mark, draw a line straight up at 90° and measure exactly 10 inches up it.
4. Join the top mark to the vertex. The angle at the vertex is 50°, because tan 50° ≈ 1.1918.
5. That gives you 130°. The outside (reflex) angle is 230°.

Where you see 230° angles

• The Earth turns 230° on its axis in about 15 h 20 min.
• A 230° 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.

Related angles

• Explement: 130°
• Half: 115°
• 30°
• 45°
• 60°
• 90°
• 120°
• 135°
• 180°