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: 'young skateboarder on paved roadway near grassy slope'. Reverse all words of length '6' in the given sentence.
Example Output: young skateboarder on paved roadway near yssarg slope

Example Input: Sentence: 'a man standing next to a parked car under a street sign'. Reverse all words of length '6' in the given sentence.
Example Output: a man standing next to a dekrap car under a teerts sign

Example Input: Sentence: 'a man holding a tennis racket at a competition'. Reverse all words of length '2' in the given sentence.
Example Output:
a man holding a tennis racket ta a competition