2.4 Draw and Measure Angles
Of you are going to measure or draw an angle, you need a protractor.
Here are two types:
Half Circle
Whole Circle

A protractor has two markings, an inner and an outer one.  It also has a center point.  It is important that you know these two markings and the center point when you are measuring and drawing angles.


Measuring Angles
Now you are going to measure the angle below.

Place the protractor over the angle with the middle at the angle’s vertex and make sure that one of the rays follows the elongated line to the markings.

Make sure that you are reading the right marks – in other words begin from 0.  Here we read from the inner marks and can see that the angle is 36°.



Drawing an Angle
To draw an angle is as easy and measuring one..

Example: Draw an angle which is 60°.

1. Begin by drawing one of the rays.

2. Place the protractor over the line and make sure that the line follows the marks out from the zero on the protractors inner markings.  Make a mark at the protractor’s center point.  This will be the angle’s vertex.

3. Measure and make a mark at 60°.

4. Draw with a straight edge from the end of the line to the marked point.

5. Mark the angle with a circular arc and write how many degrees the angle is.