2023 EOY Sec 2 ACSI P1 Q4

The diagram shows a piece of paper in the shape of a quadrant with centre \(O\) and radius \(28\) cm.
If a right cone is obtained by placing \(OA\) and \(OB\) together, find

1. the curved surface area of the cone in terms of \(pi\),

   [1]

2. the base radius of the cone.

   [2]

(Volume of Cone \( = \frac{1}{3}\pi r^2h\), Curved Surface Area of Cone \(= \pi r l\))