We are aware that an angle is made of of two rays drawn from the same point. If among the two rays one is fixed and the other one is rotated about the fixed point, it forms different angles as follows.
1. Zero Angle: If the two rays coincide initially then the angle formed is 0.
2. Acute Angle: If the two rays form angle less than 90 then it is said to be acute angle.
3. Right Angle: If the two rays form 90 then the angles are said to form right angle.
4. Obtuse Angle: If the angle formed by the two rays is above 90° and less than 180° then they are said to form an obtuse angle.
5. Straight Angle: If the two rays are on opposite sides, and form a straight line, then the angle formed is called obtuse angle.
6. Reflex Angle: If the angle formed by the two rays is above 180 and less than 360 then the angle formed is called Reflex Angle.
7. Complete Angle: If the ray which is rotating coincide with the fixed ray after completing on rotation, then angle formed is 360°.
Complementary angles definition: Pair of angles whose sum is 90° is said to be complementary angles.Example: 40° and 50°.
The sum of the angle is 40° + 50° = 90°.
Adjacent complementary angles: Adjacent complementary angles are those which are adjacent and whose sum = 90°.