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: 'a young boy plays with a phone sitting on the ground'. Reverse all words of length '6' in the given sentence.
a young boy plays with a phone sitting on the dnuorg

Sentence: 'three brown horses standing in a green field'. Reverse all words of length '5' in the given sentence.
eerht nworb horses standing in a neerg dleif

Sentence: 'a man on a ramp with a skate board in front of a crowd'. Reverse all words of length '5' in the given sentence.

a man on a ramp with a etaks draob in tnorf of a dworc