Question

find the value of angle BAD,
if angle ABD = 40°, angle DBC = 10°, angle ACD = 20° & angle DCB = 30° ​

Answer 1

Step-by-step explanation:

In quadrilateral ABCD, we have AD = BC and

∠DAB = ∠CBA.

In ΔABD and ΔBAC,

AD = BC

[Given]

AB = BA

[Common]

∠DAB = ∠CBA

[Given]

∴ Using SAS criteria, we have ΔABD ≌ ΔBAC

∵ ΔABD ≌ ΔBAC

∴ Their corresponding parts are equal.

⇒ BD = AC

Since ΔABD ≌ ΔBAC

∴ Their corresponding parts are equal.

⇒ ∠ABD = ∠BAC.

Answer 2

Step-by-step explanation:

mark BAD=x

and mark BDA=y

and