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: 'colorful kite being flown over the ocean as people are on the beach'. Reverse all words of length '3' in the given sentence.

colorful kite being flown over eht ocean as people era on eht beach