(a) In the diagram, O is the centre of the circle radius 3.2cm. If < PRQ = 42°, calculate, correct to two decimal places, the area of the: (i) minor sector POQ ; (ii) shaded part. (b) If the sector POQ in (a) is used to form the curved surface of a cone with vertex O, calculate the base radius of the cone, correct to one decimal place.
Explanation
(a) (i) Area of minor segment POQ = = = (2 decimal places) (ii) Area of in POQ = = Area of segment PQ (shaded part) = Area of sector POQ - Area of triangle = (b) Area of sector POQ = Curved surface area of the cone where r = base radius, L = slant height = 3.2cm
