Measuring angles with a protractor

Name: _____________________ Date: __________

Show your thinking with numbers, words, or a drawing.

1. Use the protractor. How many degrees is the marked angle?

1. 120

The arm along the baseline points to 0 on the inner scale, so read the inner scale.

The angle is bigger than a right angle, so the answer must be more than 90.

The other arm points to 120 on the inner scale, so the angle is 120°.

2. 140

The arm along the baseline points to 0 on the inner scale, so read the inner scale.

The angle is bigger than a right angle, so the answer must be more than 90.

The other arm points to 140 on the inner scale, so the angle is 140°.

3. 160

The arm along the baseline points to 0 on the inner scale, so read the inner scale.

The angle is bigger than a right angle, so the answer must be more than 90.

The other arm points to 160 on the inner scale, so the angle is 160°.

4. 80

The arm along the baseline points to 0 on the inner scale, so read the inner scale.

The angle is smaller than a right angle, so the answer must be less than 90.

The other arm points to 80 on the inner scale, so the angle is 80°.

5. 30

The arm along the baseline points to 0 on the inner scale, so read the inner scale.

The angle is smaller than a right angle, so the answer must be less than 90.

The other arm points to 30 on the inner scale, so the angle is 30°.

Choose a question from the printable. Use objects or a drawing to show your thinking, then explain your method to someone at home.