Measuring Angles With Protractor Worksheet
Measuring angles is a fundamental skill in geometry and trigonometry, and using a protractor is an essential tool for achieving this. A protractor is a circular or semi-circular tool used to measure angles in degrees. In this worksheet, we will explore how to use a protractor to measure angles, and provide a series of exercises for practice.
Using a Protractor to Measure Angles
To use a protractor, follow these steps:
- Place the protractor on the angle you want to measure, making sure the vertex of the angle is at the center of the protractor.
- Align the 0-degree mark on the protractor with one of the angle’s sides.
- Read the degrees on the protractor where the other side of the angle intersects the protractor’s scale.
- Record the measurement in degrees.
Important: Make sure to read the degrees from the correct scale on the protractor. The inner scale is used for measuring angles in a clockwise direction, while the outer scale is used for measuring angles in a counterclockwise direction.
Types of Angles
There are several types of angles, including:
- Acute angles: Less than 90 degrees
- Right angles: Exactly 90 degrees
- Obtuse angles: Greater than 90 degrees but less than 180 degrees
- Straight angles: Exactly 180 degrees
- Reflex angles: Greater than 180 degrees but less than 360 degrees
Measuring Angles with a Protractor Worksheet
Use the protractor to measure the angles in the following exercises:
Exercise 1
Measure the angle below using a protractor.
/\
/ \
/ \
/______\
📝 Note: Use the inner scale on the protractor to measure the angle.
Exercise 2
Measure the angle below using a protractor.
/\
/ \
/ \
/______\
📝 Note: Use the outer scale on the protractor to measure the angle.
Exercise 3
Measure the angles in the triangle below using a protractor.
A
/ \
/ \
/_____\
B C
📝 Note: Measure all three angles in the triangle.
Exercise 4
Measure the angle below using a protractor.
/\
/ \
/ \
/______\
📝 Note: Use the inner scale on the protractor to measure the angle.
Exercise 5
Measure the angles in the quadrilateral below using a protractor.
A----B
| |
| |
C----D
📝 Note: Measure all four angles in the quadrilateral.
Answer Key
Exercise 1
- Angle measurement: 60 degrees
Exercise 2
- Angle measurement: 120 degrees
Exercise 3
- Angle A: 60 degrees
- Angle B: 80 degrees
- Angle C: 40 degrees
Exercise 4
- Angle measurement: 90 degrees
Exercise 5
- Angle A: 90 degrees
- Angle B: 120 degrees
- Angle C: 60 degrees
- Angle D: 90 degrees
In conclusion, measuring angles with a protractor is a fundamental skill in geometry and trigonometry. By following the steps outlined in this worksheet, you can accurately measure angles using a protractor. Remember to use the correct scale on the protractor and to record your measurements in degrees.
What is the difference between the inner and outer scales on a protractor?
+The inner scale on a protractor is used to measure angles in a clockwise direction, while the outer scale is used to measure angles in a counterclockwise direction.
How do I measure a reflex angle using a protractor?
+To measure a reflex angle, measure the acute angle between the two sides of the angle, and then subtract that measurement from 360 degrees.
Can I use a protractor to measure angles in 3D shapes?
+No, a protractor is only used to measure angles in 2D shapes. To measure angles in 3D shapes, you need to use a different tool, such as a 3D protractor or a calculator.
