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 couple of giraffes standing in front of a metal fence'. Reverse all words of length '8' in the given sentence.
Example Output: a couple of seffarig gnidnats in front of a metal fence

Example Input: Sentence: 'a row of parked motorcycles sitting next to a white double decker bus'. Reverse all words of length '7' in the given sentence.
Example Output: a row of parked motorcycles gnittis next to a white double decker bus

Example Input: Sentence: 'a woman standing in the middle of a crowd of people'. Reverse all words of length '3' in the given sentence.
Example Output:
a woman standing in eht middle of a crowd of people