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.

Sentence: 'the redhaired woman wearing glasses is walking down the street holding a cell phone'. Reverse all words of length '3' in the given sentence.
eht redhaired woman wearing glasses is walking down eht street holding a cell phone