Hi there! I have tried solving the following question by calculating the radius of both circles and then calculating the area of the larger circle, but after that I do not know how to solve the question any further, because i can’t seem to figure out how they can find the value of Ꮎ °.

- [diagram not to scale]

The diagram shows two concentric circles both with centre O. The angle of the shaded sector is Ꮎ ° .

The radius of the larger circle is 50% greater than the radius of the smaller circle.

The total area of the smaller circle is 36π cm2.

The area of the shaded sector is 27 π/8 cm2

What is the value of Ꮎ °?

A) 15

B)8 7/16

C)16 7/8

D)22 1/2

E) 30