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 large elephant standing in the wild'. Reverse all words of length '5' in the given sentence.
Example Output: a egral elephant standing in the wild

Example Input: Sentence: 'a man and woman standing with luggage in a waiting area'. Reverse all words of length '7' in the given sentence.
Example Output: a man and woman standing with egaggul in a gnitiaw area

Example Input: Sentence: 'airplane flying in front of mountains and clouds'. Reverse all words of length '2' in the given sentence.
Example Output:
airplane flying ni front fo mountains and clouds