Let the area of smaller sector be A=1/2 r²

     Given area of bigger sector =3A=3/2  r² =1/2  r² (3 )

    hence   sum of the angles is 180 because it is a straight line i.e. diameter

        hence  +3=180     i.e. =45

            accute angle between the pair of lines =45

             tan=2((a+b)²-ab) /(a+b)

             tna45=1=2((a+b)²-ab) /(a+b)

                   (a+b)=2((a+b)²-ab)

 squaring    (a+b)²=4(a+b)²-4ab

               hence   3(a+b)²-4ab=0

                      3a²+2ab+3b²=0

 

 

Ans:(b)