The adjoining figure depicts an archery target marked with its five scoring areas from the centre outwards as Gold, Red, Blue, Black and White. The diameter of the region representing Gold score is 21 cm and each of the other bands is 10.5 cm wide.
(i) Find the area of each of the five scoring regions.
(ii) Which mathematical concept is used in the above problem?
(iii) What is its value?
