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 group of skiers standing at the base of a mountain'. Reverse all words of length '3' in the given sentence.
Example Output: a group of skiers standing at eht base of a mountain

Example Input: Sentence: 'two people are holding rackets upright on a tennis court'. Reverse all words of length '7' in the given sentence.
Example Output: two people are gnidloh stekcar thgirpu on a tennis court

Example Input: Sentence: 'a cat rests on the hood of a blue car'. Reverse all words of length '2' in the given sentence.
Example Output:
a cat rests no the hood fo a blue car