Step-by-step explanation:

Answer

Correct option is

A

40

o

□ABCD is a kite where AC and BD are diagonals intersect at point O.

∠OBC=20

o

and ∠OCD=40

o

.

We know, in kite diagonals intersect at right angles.

∴ ∠AOD=∠DOC=∠BOC=∠AOB=90

o

In △BOC,

⇒ ∠BOC+∠OBC+∠OCB=180

o

⇒ 90

o

+20

o

+∠OCB=180

o

⇒ 110

o

+∠OCB=180

o

∴ ∠OCB=70

o

⇒ AB=BC [ Adjacent sides are equal in length ]

⇒ ∠ACB=∠BAC=70

o

[ Angles opposite to equal sides are equal ]

In △AOB,

⇒ ∠ABO+∠AOB+∠OAB=180

o

⇒ ∠ABO+90

o

+70

o

=180

o

⇒ ∠ABO=20

o

⇒ ∠ABC=∠ABO+∠OBC

=20

o

+20

o

=40

o

∴ ∠ABC=40

o

.

Hope it's help