Acute, Obtuse and Reflex Angles

Q.

Classify the following angle as:
(a) Right angle
(b) Reflex angle
(c) Acute angle
(d) Obtuse angle

[1 mark]

Q.

If we consider the angle made between the hour hand and the minute hand, which of the following times make an acute angle?

1. 04:30

2. 05:00

3. 09:00

4. 06:00

Q.

Ram and Shyam were playing with a ball in the room. They somehow managed to break the window pane. Now, they both peered out of the window (shown in the figure below) and made the following statements:

Ram: The bars in the window make right angle.

Shyam: The bars in the window make acute angle.

1. Ram is correct, Shyam is also correct.

2. Ram is correct, Shyam is incorrect.

3. Ram is incorrect, Shyam is correct.

4. Both are incorrect.

Q.

If we have ∠ABC as θ, reflex ∠ABC is equal to _______.

1. $-{180}^{\circ }-\theta$​

2. ${180}^{\circ }-\theta$

3. ${360}^{\circ }-\theta$

4. ${360}^{\circ }-\theta$

Q. If the sum of two angles is less than 90°, then the angles are:

1. obtuse angles
2. right angles
3. acute angles
4. reflex angles

Q. The angle which is less than 90° is known as _______.

1. reflex angle
2. acute angle
3. right angle
4. obtuse angle

Q. Which of the following is a reflex angle?

1. 210 degrees
2. 145 degrees
3. 67 degrees
4. 90 degrees

Q. The sum of two angles is 180 ° and if one angle is obtuse, then the other one will be ___.

1. acute angle
2. right angle
3. reflex angle
4. obtuse angle

Q. Which of the following is an acute angle?

1. 195 degrees
2. 67 degrees
3. 250 degrees
4. 145 degrees

Q. The angle which is greater than 90° but less than 180 ° is known as ________.

1. reflex angle
2. acute angle
3. obtuse angle
4. right angle