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: 'someone is sitting on a elephant and messing with the seat'. Reverse all words of length '7' in the given sentence.
Example Output: enoemos is gnittis on a elephant and gnissem with the seat

Example Input: Sentence: 'a group of snow boarders pose in the snow on top of a hill'. Reverse all words of length '5' in the given sentence.
Example Output: a puorg of snow boarders pose in the snow on top of a hill

Example Input: Sentence: 'people are up and doing something fun today'. Reverse all words of length '3' in the given sentence.
Example Output:
people era up dna doing something nuf today