OpenStudy (venomous.penguin):

What is the measure of angles DAB and DCB? A) 70º and 110º B) 45º and 135º C) 20º and 160º D) 115º and 65º

OpenStudy (venomous.penguin):

OpenStudy (timamits):

sum of opposite angles of quadrilateral on a circle is 180 degree. so applying this, for angle DAB and angle DCB, we will get z. which will give all angles except angle A. you can get by applying angle sum property of a quadrilateral.

OpenStudy (venomous.penguin):

I don't get it.

OpenStudy (timamits):

Can you figure out angle DAB and angle DCB are opposite angles of the quadrilateral ABCD. Do you know the result for a cyclic quadrilateral that sum of its opposite angles is 180 degree. Do you know the result that sum of all angles of a quadrilateral is 360 degrees.