Bill has a farm. There is a dog on his farm. It is brown and black and old. It can't run fast and it always like sleeping.
There are many other animals on the farm. There are ten hens, fifteen sheep, twelve ducks, eight cows and fourteen horses. The ducks like swimming. The sheep like eating grass.
根据短文内容，判断正误。
的边长为
，
平面
，那么
到对角线
的距离是