Draw two acute angles and one obtuse angle without using a protractor. Estimate the measures of the angles. Measure them with the help of a protractor and see how much accurate is your estimate.

Angles are measured in degrees. The symbol for degree is a little circle.

The full circle is 360° (360 degree). A half circle or a straight angle is 180°. A quarter circle or a right angle is 90°.


Place the mid-point of the protractor on the Vertex of the angle. Line up one side of the angle with the Zero line of the protractor (where you see the number 0).


Read the degrees here the other side crosses the number scale.


1. Measure the angles.


2. Measure the angles. Label each angle as acute or obtuse.


3. Tasha measured an acute angle, and got 146°. The teacher pointed out that she had read the wrong set of numbers on the protractor.


4. Measure the following angles using your own protractor. If you need to, make the sides of the angles longer with a ruler.


5. Draw four dots and connect them so that you get a quadrilateral.


Measure all the angles of your quadrilateral. Then add the angle measure.


53