In this task, you need to remove 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 boy looks excitedly at his birthday cake with his friend'. Remove all words of length '9' in the given sentence.
Example Output: a boy looks at his birthday cake with his friend

Example Input: Sentence: 'a group of young children standing around each other'. Remove all words of length '1' in the given sentence.
Example Output: group of young children standing around each other

Example Input: Sentence: 'a sheep grazing in a field above a pond'. Remove all words of length '2' in the given sentence.
Example Output:
a sheep grazing a field above a pond