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.
Input: Sentence: 'a backyard area that has an outdoor table umbrella and chairs set on an grass lawn with a wooden fence enclosing the yard area'. Reverse all words of length '7' in the given sentence.

a backyard area that has an roodtuo table umbrella and chairs set on an grass lawn with a wooden fence enclosing the yard area