The diameter of the base of a right circular cylinder is 28 cm and its height is 21 cm. Find its 
(i) curved surface area 
(ii) total surface area 
(iii) volume

Diameter of the base of a right circular cylinder is 28 cm
Radius of the base of a right circular cylinder (r) is 14 cm 
Height of a right circular cylinder is 21 cm.
(i) Curved surface area of a right circular cylinder = 2πrh = 2 × × 14 × 21 
                                                                          = 1848 cm²
(ii) Total surface area of a right circular cylinder = 2πr(r + h)
                                                               = 2 × × 14(14 + 21)
                                                               = 2 × × 14 × 35
                                                               = 3080 cm²
(iii) Volume of a right circular cylinder = π r²h =× 14 × 14 × 21 = 12936 cm³.