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: 'two giraffes are walking through a field of prairie grass'. Reverse all words of length '1' in the given sentence.
Example Output: two giraffes are walking through a field of prairie grass

Example Input: Sentence: 'a person is riding a skateboard in a skateboard park'. Reverse all words of length '10' in the given sentence.
Example Output:
a person is riding a draobetaks in a draobetaks park