Measure Angles With A Protractor - Independent Practice Worksheet ... - Free Printable

Explanation:
To measure an angle using a protractor, follow these steps:

1. Place the center of the protractor (the small hole or mark) directly on the vertex of the angle. The vertex is the point where the two lines meet. In this case, the vertex is point O.

2. Align one of the rays of the angle (like ray OA) with the zero line of the protractor. The zero line is the straight edge that goes from 0 to 180 degrees.

3. Look at the other ray (ray OB) and see where it crosses the numbers on the protractor. That number is the measure of the angle.

4. Make sure you read the correct scale. Some protractors have two scales: one going from 0 to 180 degrees on the top, and another from 180 to 0 on the bottom. Use the scale that starts at 0 where the ray OA is aligned.

5. Write down the number you read. That’s the size of the angle in degrees.

For example, if ray OA is on the 0-degree mark and ray OB crosses the protractor at 45, then the angle AOB is 45 degrees.

Now, apply this to each of the five angles in the worksheet:

1. Angle AOB: The ray OB goes up and to the left from O. When you line up OA with the 0-degree line, OB crosses at about 60 degrees. So, the angle is 60°.

2. Angle AOB: Ray OA goes to the right, and ray OB goes straight up. This forms a perfect corner, like the corner of a square. That’s a right angle, which is 90°.

3. Angle AOB: Ray OA goes to the right, and ray OB goes up and to the left, but it’s more open than the first one. When you measure it, it crosses at about 120 degrees. So, the angle is 120°.

4. Angle AOB: Ray OA goes to the right, and ray OB goes up and to the left, but it’s a smaller angle than the first one. It crosses at about 30 degrees. So, the angle is 30°.

5. Angle AOB: Ray OA goes to the right, and ray OB goes up and to the left, but it’s more open than the fourth one. It crosses at about 150 degrees. So, the angle is 150°.

Final Answer:
1. 60°
2. 90°
3. 120°
4. 30°
5. 150°