TASK 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.
PROBLEM: Sentence: 'small blue and red bird standing on rear of zebra'. Reverse all words of length '8' in the given sentence.

SOLUTION: small blue and red bird gnidnats on rear of zebra

PROBLEM: Sentence: 'a skateboarder in mid air during a trick'. Reverse all words of length '6' in the given sentence.

SOLUTION: a skateboarder in mid air gnirud a trick

PROBLEM: Sentence: 'a cat is on a shelf looking in the mirror'. Reverse all words of length '5' in the given sentence.

SOLUTION:
a cat is on a flehs looking in the mirror