Question

three consecutive vertices of parrelogeam are (1,2) (1,0),(4,0). find the fourth vertex

Answer 1

As we know that , diagonals of llgm are equal,

so, BD=AC

by midpoint formula , we will find coordinates of mid point of line AC.

x=x1+x2/2=1+4/2=5/2

y=y1+y2/2=2+0/2=1

so, coordinates of midpoint AC  is O(5/2,1)

and we know that BD =AC

then by midpoint formula we will find  coordinates of vertex D

X=X4+1/2=5/2

X4+1=5

X4=4

then,  Y=y4+0/2=1

         y4=2

so the coordinate of vertex Dis D(X4,y4)=D(4,2)

Please see the attachment for better understanding......