7 The area of a sector of a circle is \(36.288 \mathrm {~cm} ^ { 2 }\). The angle of the sector is \(\theta\) radians and the radius of the circle is \(r \mathrm {~cm}\).
- Find an expression for \(\theta\) in terms of \(r\).
The perimeter of the sector is 24.48 cm .
- Show that \(\theta = \frac { 24.48 } { r } - 2\).
- Find the possible values of \(r\).