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: 'the three giraffes are standing on the grassland'. Remove all words of length '2' in the given sentence.
Example Output: the three giraffes are standing the grassland

Example Input: Sentence: 'a sign post with an eagle on the top in a marshy park area'. Remove all words of length '6' in the given sentence.
Example Output: a sign post with an eagle on the top in a park area

Example Input: Sentence: 'a couple of brightly colored tooth brushes together'. Remove all words of length '6' in the given sentence.
Example Output:
a of brightly colored tooth brushes together