Find the measure of b

Step-by-step explanation:

Hi there!

From the above figure;

Let "x" be an unknown angle.

Then;

100° + X = 180°. { The opposite angles of cyclic quadrilateral is supplementary}

X = 180°-100°

Therefore, X= 80°.

Now;

X+b = 180°. {linear pair}

80° + b = 180°

Therefore, b = 100°.

[Next method:

b = 100° {When any side of cyclicquadrilateral is extended the external angle is equal to opposite interior angle.]

Hope it helps.

step-by-step explanation:

a and d