**??? - 2016 JUNE Q6**

A sector of a circle has radius

*r*cm and sector angle θ radians. It is divided into two regions, A and B. Region A is an isosceles triangle with the equal sides being of length*a*cm, as shown in Fig. 6.(i) Express the area of B in terms of

(ii) Given that

*a*,*r*and θ. [2](ii) Given that

*r*= 12 and θ = 0 8. , find the value of a for which the areas of A and B are equal. Give your answer correct to 3 significant figures. [2]