Question

Define the following terms:
(i) Angle
(ii) Interior of an angle
(iii) Obtuse angle
(iv) Reflex angle
(v) Complementary angles
(vi) Supplementary angles

Answer 1

(i) Two rays OA and OB, with a common end-point O, form an angle AOB that is represented as $\angle AOB$.


(ii) The interior of an angle is the set of all points in its plane, which lie on the same side of OA as B and also on the same side of OB as A.


(iii) An angle greater than $90°$ but less than $180°$ is called an obtuse angle.



(iv) An angle greater than $180°$ but less than $360°$ is called a reflex angle.



(v) Two angles are said to be complementary if the sum of their measures is $90°$.

(vi) Two angles are said to be supplementary if the sum of their measures is $180°$.