In an isosceles triangle ABC,the bisector of angle B and angle C meet at O.If angle BOC= 140 degree,then angle A measures ?
Answer :
We form our diagram from given information , As :
Here , BOC = 140
And
AB = AC ( triangle ABC is a isosceles triangle ) From base angle theorem we get
ABC = ACB = x , So
OBC = OCB =
Now from angle sum property in triangle BOC we get
OBC + OCB + BOC = 180 , Substitute values and get
So,
ABC = ACB = 40
Now we get from angle property in triangle ABC
ABC + ACB + BAC = 180
40 + 40 + BAC = 180
BAC = 100 ( Ans )
We form our diagram from given information , As :
Here , BOC = 140
And
AB = AC ( triangle ABC is a isosceles triangle ) From base angle theorem we get
ABC = ACB = x , So
OBC = OCB =
Now from angle sum property in triangle BOC we get
OBC + OCB + BOC = 180 , Substitute values and get
So,
ABC = ACB = 40
Now we get from angle property in triangle ABC
ABC + ACB + BAC = 180
40 + 40 + BAC = 180
BAC = 100 ( Ans )