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: 'an aerial view of four people walking down the street under three colored umbrellas'. Reverse all words of length '2' in the given sentence.

na aerial view fo four people walking down the street under three colored umbrellas