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.

Example Input: Sentence: 'a person in a rowboat under an umbrella'. Reverse all words of length '5' in the given sentence.
Example Output: a person in a rowboat rednu an umbrella

Example Input: Sentence: 'a pinto horse walking in a coral with two people'. Reverse all words of length '2' in the given sentence.
Example Output: a pinto horse walking ni a coral with two people

Example Input: Sentence: 'a woman with blue gloves is at a kitchen sink'. Reverse all words of length '1' in the given sentence.
Example Output:
a woman with blue gloves is at a kitchen sink