Question

The vertices of a parallelogram are at (4, 1), (1, 2 ), (−5, −1 ) and (−2, −2 ). Find the angles at vertex A

and also at vertex B.​

Answer 1

Answer:

Let the three vertices of parallelogram ABCD be A( - 1,2) , B(4,1) and C(7,6) Let the fourth vertex be D(a,b) By joining AC and BD intersect at point O i.e, diagonals of parallelogram bisect each other Mid point of AC = ( -1+ 72 , 2 + 62 ) = (3,4) Mid point of BD = ( 4 + a2 , 1 + b2 ) 4 + a2 = 3 1 + b2 = 4 a = 2,b = 7 The coordinate of fourth vertex = (2,7)