In these lessons, we will look at how to use a protractor to

- draw an angle less than 180˚
- draw an angle greater than 180˚ (reflex angle)

**Related Pages**

Construct angles with the use of compasses instead of protractors

More Geometry Lessons

**Example:**

Draw an angle *ABC*, which is 55˚.

Step 1: Draw a line *BC* and mark *B* as the vertex.

Step 2: Place the centre of the protractor at the vertex *B* and adjust the base line to be aligned to *BC*.

Step 3: Find 55˚ on the outer scale of the protractor and mark that point as point *A*.

Step 4: Remove the protractor and draw a line from point *B* to point *A*

Step 5: Label and *ABC*

**How to draw and measure angles using a protractor?**

**Examples:**

Draw and measure

a) a 110° angle.

b) a 27° angle

**Measuring angles using a protractor (acute angles)**

**Measuring Angles with Protractors (obtuse angles)**

To draw a reflex angle (i.e. angle greater than 180º and less than 360º), we need to

- Subtract the reflex angle from 360º.
- Draw the resulting angle as described above.
- Mark the required angle which is outside the one that has been drawn.

**Example:**

Draw an angle *ABC* = 250˚

To draw the reflex angle, 250˚, we first draw the angle obtained by subtracting 250˚ from 360˚ which is 360˚ – 250˚ = 110˚

Step 1: Draw the line *BC*

Step 2: Place the centre of the protractor at the vertex *B* and adjust the base line to be aligned to *BC*.

Step 3: Find the angle 110˚ on the protractor (inner) scale and mark that as point *A*.

Step 4: Remove the protractor and draw a line from point *B* to point *A*.

Step 5: Label the reflex angle *ABC*

**How to use a protractor to draw acute angles, right angles, obtuse angles and reflex angles?**

**How to draw a Reflex Angle?**

**How to Measure a Reflex Angle Using a Protractor?**

Try the free Mathway calculator and
problem solver below to practice various math topics. Try the given examples, or type in your own
problem and check your answer with the step-by-step explanations.

We welcome your feedback, comments and questions about this site or page. Please submit your feedback or enquiries via our Feedback page.