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 and women embracing each other in front of trees'. Reverse all words of length '4' in the given sentence.
Example Output: a man and women embracing hcae other in front of trees

Example Input: Sentence: 'a couple of toothbrushes that are on a towel'. Reverse all words of length '6' in the given sentence.
Example Output: a elpuoc of toothbrushes that are on a towel

Example Input: Sentence: 'a herd of zebra standing in a forest'. Reverse all words of length '1' in the given sentence.
Example Output:
a herd of zebra standing in a forest