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 boy with a red cloak standing alongside a figure with a red cloak and dragon mask'. Reverse all words of length '1' in the given sentence.

a boy with a red cloak standing alongside a figure with a red cloak and dragon mask