A goat is tethered to one end of a rope of length 20m, while the other end is fixed at the centre of a large circular field. There is a square elevated platform with sides of 10 m on the field such that one corner of the elevated square platform councides with centre of the circular field. If the goat is unable to mount the square elevated platform, what is the total area the goat will be able to graze?
(a) 3 × 100 π
(b) 3.5 × 100 π
(c) 4 × 100 π
(d) 100(3π + 1)