Q.9 In the following figure:
(i) Is $$\angle$$1 adjacent to angle 2?
(ii) Is $$\angle$$AOC adjacent to angle AOE?
(iii) Do $$\angle$$ COE and $$\angle$$ EOD form a linear pair?
(iv) Are $$\angle$$ BOD and $$\angle$$ DOA supplementary?
(v) Is $$\angle$$ 1 vertically opposite angle to angle 4?
(vi) What is the vertically opposite angle of $$\angle$$ 5?

###### Answer :

(i) Yes, $$\angle$$ 1 and $$\angle$$ 2 are adjacent angles.
because it's one arm (OC) is common
(ii) No, $$\angle$$ AOC is not adjacent to $$\angle$$ AOE.
[ because OC and OE do not lie on either side of common arm OA] .
(iii) Yes, $$\angle$$ COE and $$\angle$$ EOD form a linear pair of angles.
(iv) Yes, $$\angle$$ BOD and $$\angle$$ DOA are supplementary.
[Because $$\angle$$ BOD + because $$\angle$$DOA = 180°]
(v) Yes, $$\angle$$ 1 is vertically opposite to $$\angle$$ 4.
(vi) Vertically opposite angle of $$\angle$$ 5 is $$\angle$$ 2 + $$\angle$$ 3 i.e. angle BOC.