Requirement is related to Need. Need is related to Required. 
Month is related to Measure. Measure is related to Math. Math is related to Course. Course is a synonym of Aim. 
Requirement <--RelatedTo--> Need <--RelatedTo--> Required 
Month <--RelatedTo--> Measure <--RelatedTo--> Math <--RelatedTo--> Course <--Synonym--> Aim 