Angle, perimeter and area of a circular sector from its radius and arc length

In the diagram below, \(O\) is the centre of a circle of radius \(6\) cm. The points \(A\) and \(B\) lie on the circle, and the shaded region is the minor sector \(AOB\).

The angle \(A\hat{O}B\) is \(\theta\) radians, and the minor arc \(AB\) has length \(9\) cm.

1. Find \(\theta\).[2]
2. Find the perimeter of the sector \(AOB\).[2]
3. Find the area of the sector \(AOB\).[2]