Angles and Protractors Quiz

Grade 4 · Math · Quiz

Test your ability to classify, measure, and work with angles.

Questions

1. Which angle type measures more than 90° but less than 180°?

   1. Acute
   2. Right
   3. Obtuse
   4. Straight
   Show answer

   Answer: Obtuse

   An obtuse angle is greater than 90° and less than 180°. Acute is less than 90°; right is exactly 90°; straight is exactly 180°.

2. You measure an angle with a protractor and it reads 72°. What type of angle is it?

   1. Obtuse
   2. Straight
   3. Right
   4. Acute
   Show answer

   Answer: Acute

   72° is less than 90°, so it is an acute angle.

3. Two angles together form a straight angle. One angle is 55°. What is the other angle?

   1. 35°
   2. 45°
   3. 125°
   4. 135°
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   Answer: 125°

   Supplementary angles add up to 180°. 180° − 55° = 125°.

4. A full rotation around a point equals _____ degrees.

   Show answer

   Answer: 360

   A complete rotation around any point is always 360°. A half turn is 180° and a quarter turn is 90°.

5. Which angle correctly describes the corner of a square?

   1. Acute (less than 90°)
   2. Right (exactly 90°)
   3. Obtuse (more than 90°)
   4. Straight (180°)
   Show answer

   Answer: Right (exactly 90°)

   All four corners (angles) of a square are right angles measuring exactly 90°.

6. An angle of 90° and an angle of 90° are supplementary angles.

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   Answer: True

   Supplementary angles add up to 180°. 90° + 90° = 180°, so yes, two right angles are supplementary.

7. The clock shows 3:00. What type of angle is formed between the hour and minute hands?

   1. Acute
   2. Obtuse
   3. Right
   4. Straight
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   Answer: Right

   At 3:00, the minute hand points to 12 and the hour hand points to 3. That is exactly a quarter turn, or 90° — a right angle.

8. If one angle in a complementary pair is 38°, what is the other angle?

   1. 52°
   2. 62°
   3. 142°
   4. 152°
   Show answer

   Answer: 52°

   Complementary angles add up to 90°. 90° − 38° = 52°.

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