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 man being towed behind a boat on a board'. Reverse all words of length '4' in the given sentence.
Example Output: a man being towed behind a taob on a board

Example Input: Sentence: 'an aerial view of a small bathroom stall'. Reverse all words of length '8' in the given sentence.
Example Output: an aerial view of a small moorhtab stall

Example Input: Sentence: 'two skiers on top of a ski slope'. Reverse all words of length '6' in the given sentence.
Example Output:
two sreiks on top of a ski slope