In this task, you need to reverse all words of a given length in the sentence. The number of letters in a word determine its length. For example, the length of the word "apple" is 5.

Example Input: Sentence: 'a small white dog with a hat on his rear end'. Reverse all words of length '3' in the given sentence.
Example Output: a small white god with a tah on sih rear dne

Example Input: Sentence: 'a grey clock tower with trees and wall below'. Reverse all words of length '5' in the given sentence.
Example Output: a grey kcolc rewot with seert and wall woleb

Example Input: Sentence: 'a woman with a life jacket on holding onto a rope while engaging in a water sport'. Reverse all words of length '8' in the given sentence.
Example Output:
a woman with a life jacket on holding onto a rope while gnigagne in a water sport