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: 'dog lying on bottom of enclosed area with people'. Reverse all words of length '5' in the given sentence.
Example Output: dog gniyl on bottom of enclosed area with people

Example Input: Sentence: 'a couple of men on a court holding tennis rackets'. Reverse all words of length '2' in the given sentence.
Example Output: a couple fo men no a court holding tennis rackets

Example Input: Sentence: 'a train at a standstill boarding at a train station'. Reverse all words of length '2' in the given sentence.
Example Output:
a train ta a standstill boarding ta a train station