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 elephant standing next to a forest full of trees'. Reverse all words of length '5' in the given sentence.
Example Output: a llams elephant standing next to a forest full of seert

Example Input: Sentence: 'the man smiles while holding a small boy'. Reverse all words of length '5' in the given sentence.
Example Output: the man smiles elihw holding a llams boy

Example Input: Sentence: 'an open suit case in front of a green wall'. Reverse all words of length '4' in the given sentence.
Example Output:
an nepo tius esac in front of a green llaw