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: 'two giraffes standing next to a fence trying to reach the grass'. Reverse all words of length '6' in the given sentence.
Example Output: two giraffes standing next to a fence gniyrt to reach the grass

Example Input: Sentence: 'he is a serious baseball player and is ready for the pitch'. Reverse all words of length '5' in the given sentence.
Example Output: he is a serious baseball player and is ydaer for the hctip

Example Input: Sentence: 'a group of elephants in the water with a group of people'. Reverse all words of length '1' in the given sentence.
Example Output:
a group of elephants in the water with a group of people