Do you know totally how many different types of angles we have and what are that angles? Those are studying in class 6 or 7, this topic is very important. Basic things about the angles we are going to learn in lower class only.
What is an angle? Union of two rays is called an angle. We can also define angle as the amount of rotation of terminal ray with respect to fixed ray. Generally the unit of measurement of an angle is degree.
Different types of angles are given below with diagram:
An angle which lying between 0° to 90° or An angle which is more than 0° and less than 90° is called An Acute angle.
10° , 18°, 45°, 56°, 72°, 89° are the acute angles.
An angle whose measure is exactly equal to 90° is called a right angle.
An angle which is lying between 90° to 180° is called obtuse angle.
93°, 100°, 135°, 113° and 99° are obtuse angles.
An angle whose measure is exactly equal to 180° is called straight angle.
An angle which is more than 180° and less than 360° is called reflex angle.
192°, 245°, 230°, 289°, 320° and 359° are called reflex angles.
An angle whose measure is exactly 360° is called complete angle.
An angle whose measure is exactly 0° is called zero angle.
Some special types of angle:
If the sum of any two angles is equal to 90° then that two angles are called complementary angles.
14° and 76° are complementary angles.
25° and 65° are complementary angles
If the sum of any two angles is equal to 180° then that two angles are called supplementary angles.
Generally the given two angles are called adjacent angles suppose if they have a common vertex and a common arm.
In the above diagram
∠DAC and ∠CAB have one common vertex i.e. A and one common arm i.e.AC so these two angles are called adjacent angles.