怎么使用量角器

To use a protractor, follow these steps:

1. Place the center of the protractor on the vertex of the angle you want to measure.
2. Align one side of the angle with the baseline of the protractor.
3. Read the measurement where the other side of the angle intersects with the protractor scale.
4. Make sure to read the correct unit of measurement (degrees or radians) based on the protractor you are using.

If you need further assistance or clarification, feel free to ask!