Question

if in a quadrilateral abcd, ad and bo are the bisector of angle A and angle B respectively option
a ​

Answer 1

∠AOB=

2

1

(∠C+∠D)

Step-by-step explanation:

ABCD is a quadrilateral

To prove : ∠AOB=

2

1

(∠C+∠D)

AO and BO is bisector of A and B

∠1=∠2∠3=∠4...(1)

∠A+∠B+∠C+∠D=360

(Angle sum property)

2

1

(∠A+∠B+∠C+∠D)=180...(2)

In △AOB

∠1+∠3+∠5=

2

1

(∠A+∠B+∠C+∠D)

∠1+∠3+∠5=∠1+∠3+

2

1

(∠C+∠D)

∠AOB=

2

1

(∠C+∠D)

Answer 2

Answer:

I) angle a +angle b+ angle c =180° is the correct answer