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 person wearing a black jacket is standing next to a horse'. Reverse all words of length '8' in the given sentence.
Example Output: a person wearing a black jacket is gnidnats next to a horse

Example Input: Sentence: 'a dog lays next to a bag on a couch'. Reverse all words of length '4' in the given sentence.
Example Output: a dog syal txen to a bag on a couch

Example Input: Sentence: 'there i a cookie on the table next to the orange'. Reverse all words of length '6' in the given sentence.
Example Output:
there i a eikooc on the table next to the egnaro