Question

In given fig abcd is a cyclic quadrilateral that adb=40 and dca=70 find measure of dab

Answer 1

Answer:

∠BCA = ∠ADB = 40° [angles in same segment of a circle are equal]

Now, ∠BCD = 70° + 40° = 110°

∠DAB + ∠BCD = 180°

∠DAB = 180° - 110°

⇒ ∠DAB = 70°

Answer 2

Question - Picture is attached for reference.

Given - Angle ADB and angle DCA

Find - Angle DAB

Solution - Angle ADB and Angle ACB will be same as they are in same segment.

So, Angle ADB = Angle ACB = 40°.

Angle DCB = Angle ACB + Angle DCA

Angle DCB = 40 + 70

Angle DCB = 110°

Now, as per the property of quadrilateral, Angle DCB and Angle DAB will sum up to 180°.

110 + Angle DAB = 180

Angle DAB = 180 - 110

Angle DAB = 70°

Hence, Angle DAB is 70°.