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: 'a croissant on a plate and a cup of coffee and a tray'. Reverse all words of length '5' in the given sentence.

a croissant on a etalp and a cup of coffee and a tray