Q: On a large ground, there is a straight tall vertical wall of length 28 m. A goat is tied to a point on the ground which is at the middle of the wall, using a rope. If the length of the rope is 21 m, what is the area of the region (in sq. m) around the wall that the goat can access?
(a)847
(b)851
(c)693
(d)654