Question

ABCD is a cyclic quadrilateral, /_ D=30°, /_C= 80°, find /_A.​

Answer 1

Answer:

Correct option is A)

Given,

∠ADB=300 and ∠DCA=800.

Now,

∠DCA=∠DBA=800   (Angle subtended by same chord are equal).

In △ADB,

∠ADB+∠DBA+∠DAB=1800    (Sum of angles in triangle is 1800)

⟹ ∠DAB=1800−800−300=700.

Hence, the measure of ∠DAB is 700.

Therefore, option A is correct.

Answer 2

Answer:

ABCD is a cyclic quadrilateral, /_ D=30°, /_C= 80°, find /_A.

Correct option is A)

Given,

∠ADB=300 and ∠DCA=800.

Now,

∠DCA=∠DBA=800   (Angle subtended by same chord are equal).

In △ADB,

∠ADB+∠DBA+∠DAB=1800    (Sum of angles in triangle is 1800)

⟹ ∠DAB=1800−800−300=700.

Hence, the measure of ∠DAB is 700.

Therefore, option A is correct.