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 tennis player is swinging at a tennis ball'. Reverse all words of length '2' in the given sentence.
Example Output: a tennis player si swinging ta a tennis ball

Example Input: Sentence: 'an image of a group of people sitting in the snow'. Reverse all words of length '6' in the given sentence.
Example Output: an image of a group of elpoep sitting in the snow

Example Input: Sentence: 'a vintage pickup truck is displayed at an outdoor auto show'. Reverse all words of length '7' in the given sentence.
Example Output:
a egatniv pickup truck is displayed at an roodtuo auto show