Definition: 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.
Input: Sentence: 'the pair of giraffes trot about their enclosure as zoo patrons watch in awe'. Reverse all words of length '2' in the given sentence.

the pair fo giraffes trot about their enclosure sa zoo patrons watch ni awe