If the opposite angles of a cyclic quadrilateral are in the ratio 3:7, then the measure of the bigger angle among the two is

Correct option is B

Given : 

the opposite angles of a cyclic quadrilateral are in the ratio 3 : 7 . 

Concept Used: 

​A cyclic quadrilateral has the property that the sum of its opposite angles is180∘180^\circ180°180\degree180°. 

Solution :  

Let the opposite angles be $3x$and$7x$.​

The sum of the opposite angles is $$180\degree$$​ 180∘180^\circ
:

3 x + 7 x = $$180\degree$$

10 x = $$180\degree$$

x = $$18\degree$$

Now, 

The smaller angle is 3x=3×18∘=54∘3x = 3 \times 18^\circ = 54^\circ3x=3×18°\degree°​ 
= 54°54\degree54°​​​

The larger angle is 7x=7×18∘=126∘7x = 7 \times 18^\circ = 126^\circ7x=7×18°\degree°​ 
= 126°126\degree126°​

The correct answer is option ( b ) 126$$\degree$$​​