Three vertices of parallelogram taken in order are (1,2) (2,4) and (3,7). Find its fourth vertex

Three vertices of parallelogram taken in order are (1,2) (2,4) and (3,

1.	Three vertices of parallelogram taken in order are (1,2) (2,4) and (3,7). Find its fourth vertex
Answer» Join it\'s diagonals and then by mid point formula Find its fourth vertex by distance formula I think.....What about u??