on the 0 30. In the given figure, O is the centre. Find angle
OCB
Answers
Givne ∠OAB=30
;∠OCB=55
o
In △AOB,AO=OB (both are radius)
∠OBA=∠BAO=30
o
(angles opposite to equal sides are equal)
In △AOB, ∠AOB+∠OBA+∠BAO=180
o
∠AOB+30
o
+30
o
=180
o
∠AOB=180−60=120
o
Now In △OCB, OC=OB (Radius)
∠OCB=∠OBC=55
o
(Angles opposite to equal sides are equal)
In △OCB, ∠COB+∠OCB+∠CBO=180
o
∠COB=180−55−55
=180−110
=∠COB=70
o
=∠BOC
From ∠AOB=120
o
∠AOC+∠COB=120
o
∠AOC+70
o
=120
∠AOC=120−70
∠AOC=50
o
∴∠AOC=50
o
,=∠BOC=70
o
Answer:
Givne ∠OAB=30
;∠OCB=55
o
In △AOB,AO=OB (both are radius)
∠OBA=∠BAO=30
o
(angles opposite to equal sides are equal)
In △AOB, ∠AOB+∠OBA+∠BAO=180
o
∠AOB+30
o
+30
o
=180
o
∠AOB=180−60=120
o
Now In △OCB, OC=OB (Radius)
∠OCB=∠OBC=55
o
(Angles opposite to equal sides are equal)
In △OCB, ∠COB+∠OCB+∠CBO=180
o
∠COB=180−55−55
=180−110
=∠COB=70
o
=∠BOC
From ∠AOB=120
o
∠AOC+∠COB=120
o
∠AOC+70
o
=120
∠AOC=120−70
∠AOC=50
o
∴∠AOC=50
o
,=∠BOC=70
o