Math worksheet for students to practice measuring angles using a protractor.

To determine the measure of each angle, we look at where the second ray (the moving arm) crosses the protractor scale.

Key Rule:
* If the bottom ray points to the right (towards 0 on the inner scale), read the inner numbers.
* If the bottom ray points to the left (towards 0 on the outer scale), read the outer numbers.

Here is the step-by-step solution for each problem:

1) The bottom ray points right. We read the inner scale. The line crosses exactly at 70°.
2) The bottom ray points right. We read the inner scale. The line crosses exactly at 30°.
3) The bottom ray points right. We read the inner scale. The line crosses exactly at 45°.
4) The bottom ray points right. We read the inner scale. The line crosses exactly at 60°.
5) The bottom ray points left. We read the outer scale. The line crosses exactly at 50°.
6) The bottom ray points right. We read the inner scale. The line is between 10 and 20, right in the middle. That makes it 15°.
7) The bottom ray points right. We read the inner scale. The line crosses exactly at 50°.
8) The bottom ray points left. We read the outer scale. The line crosses exactly at 70°.
9) The bottom ray points right. We read the inner scale. The line is between 0 and 10, right in the middle. That makes it 5°.
10) The bottom ray points right. We read the inner scale. The line crosses exactly at 20°.

Final Answer:
1. 70°
2. 30°
3. 45°
4. 60°
5. 50°
6. 15°
7. 50°
8. 70°
9. 5°
10. 20°