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3. Draw the following angles using a protractor.
(a) 40° (b) 50° (c) 75° (d) 125° (e) 142°
(f) 25° (g) 175° (h) 120° (i) 90° (j) 165°

TYPES OF ANGLES

Angles are of different types.

1. Acute angle: An angle whose measure is less than 90° is called A
an acute angle.
In the following figure, ∠ABC = 50°

Thus, ∠ABC is an acute angle. 50°
B C
Acute angle

2. Right angle: An angle whose measure is 90° is called a right X
angle.
In the following figure, ∠XYZ = 90°

Thus, ∠XYZ is a right angle. 90°
Y Z
Right angle

3. Obtuse angle: An angle whose measure is more than 90° and P
less than 180° is called an obtuse angle.
In the following figure, ∠PQR = 120° 120°

Thus, ∠PQR is an obtuse angle. Q R
Obtuse angle

4. Straight angle: An angle which is of 180° is called a
straight angle. 180°

In the following figure, ∠COD = 180° C O D
Thus, ∠COD is a straight angle. Straight angle

5. Reflex angle: An angle greater than 180° and less than 360° is R
called a reflex angle.
Here, ∠ROK = 250°.

So, ∠ROK is a reflex angle.
O K
250°
Reflex angle

6. Complete angle: An angle whose measure is equal to 360° is
called a complete angle. 360°
The following angle measures 360°. X
Y Z
Thus, ∠XYZ is a complete angle. Complete angle

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