Question

ABCD is a parallelogram where A (x,y), B(1,2).C(4.3) and D (7.6).
Find
(i) Co-ordinates of A
(1) Equation of AC.​

Answer 1

Step-by-step explanation:

Let the three vertices of parallelogram ABCD be A(−1,2),B(4,1)andC(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= (

2

−1+7

,

2

2+6

)=(3,4)

Mid point of BD =(

2

4+a

,

2

1+b

)

2

4+a

=3

2

1+b

=4

∴a=2,b=7

∴ The coordinate of fourth vertex =(2,7)