in figure lines ab and cd intersect each other at point o.if angle aoc : angle boc =5:7 find all the angles
Answers
Answer:
angle AOC = angle BOD =75
angle BOC = angle AOD = 105
Step-by-step explanation:
measure of angle is x
angle AOC = 5x
angle AOD = 7x
hence,
ang AOC + ang AOD = 180.....linear pair
5x + 7x = 180
12x=180
x= 180
x= 180 / 12 = 15
hence, angle AOC = angle BOD.......opposite angles
angle AOC = angle BOD = 5x = 5 x 15 = 75
similarly,
angle BOC = angle AOD .opposite angles
angle BOC = angle AOD = 7x = 7 x 15
= 105
hope it's helps you
mark it as brainlist
follow me nd thnxx my answer
Given :-
Lines AB and CD intersect each other at a point O .
∠AOC : ∠BOC = 5 : 7
Required to find :-
- Measures of all the angles
Concept used :-
- Vertically opposite angles are equal
- Sum of a linear pair is supplementary
Solution :-
We can solve this question in 2 methods !
1st method :-
Given :-
∠AOC : ∠BOC = 5 : 7
So,
Let,
∠AOC = 5x°
∠BOC = 7x°
( Refer to the attachment )
From the diagram we can conclude that ;
∠AOC and ∠BOC form an linear pair
So,
∠AOC + ∠BOC = 180°
[Reason :- Sum of a linear pair is supplementary ]
Hence,
5x° + 7x° = 180°
12x° = 180°
x° = 180°/12
x° = 15°
So,
∠AOC = 5x = 5 ( 15 )° = 75°
∠BOC = 7x = 7 ( 15 )° = 105°
Now,
We can conclude that ;
∠AOC = ∠BOD
∠ BOC = ∠AOD
[ Reason :- Vertically Opposite angles are equal ]
Hence,
This implies ,
∠BOD = 75°
∠AOD = 105°
__________________________________________________
2nd method :-
Consider the given ratio ;
That is ,
∠AOC : ∠BOC = 5 : 7
So,
Let,
∠AOC = 5x°
∠BOC = 7x°
Now,
Refer to the attachment ,
From the given diagram we can conclude that ;
∠AOC = ∠BOD
∠BOC = ∠AOD
[ Reason : Vertically Opposite angles ]
This implies ,
∠BOD = 5x°
∠AOD = 7x°
However,
We can also conclude that ,
∠AOC + ∠BOC + ∠AOD + ∠BOD = 360°
[ Reason :- They form a complete angle ]
So,
5x° + 7x° + 7x° + 5x° = 360°
24x° = 360°
x° = 360°/24
x° = 15°
Hence,
∠AOC = 5x° = 5 ( 15 )° = 75°
∠BOC = 7x° = 7 ( 15 )° = 105°
This implies
=> ∠BOD = 75°
=> ∠AOD = 105°