A goat tethered at a rope of length L = 10m grazes an area = πL²
(a disc centered at the post)
Here the problem is a little harder as there is a wall of height h = 2m between the goat and the post !
(the goat can't go over the wall, the wall is "endless" (length > 2L), of neglectable width)
The post is right at the bottom of the wall, on the opposite side to the goat. Grazed area ?
The post is at distance d = 1m of the wall.